House plants. Sure a few mass-market plants are dirt cheap, but soon you get into unusual plants, plants with special needs, hundreds/thousands of plants, grow lights, grow racks, terrariums, automated watering systems…

Woodworking. You start with a few tools to fix things in your house, and suddenly, you got vintage handtools worth thousands of euros and you seriously speak of installing your "shop".

Music production. You start with pirated FL Studio and sone freeware plugins and the next thing you know is you're planing your hone studio with room treatment, expensive monitors, an expensive interface, aonther evrn more expensive interface, that one vintage compressor you absolutely need, a tape machine, and then you want I synthesizer, just a small, versaitle one, and next thing you know is you're buying the second euro rack for your mod synth because there wasn't enough space in the first one, because you need that one filter, and since you got lots of free slots now, why not buy some more fx. Fx can't hurt, right? And maybe one oscillator, you always wanted a fifth one...

When I first got into VRChat to hang out with some friends, I thought maybe I could survive just playing on desktop for free. Now, a couple thousand dollars later, I own a Valve Index, extra base stations and 4 trackers for full-body tracking.

Espresso.

It started with a second hand cheap machine from my grandmother as a gift for Christmas.

Then I bought a delonghi grinder for £50 and a used delonghi dedica for £60.

Then I upgraded the grinder to a baratza sette for £300.

Then I upgraded the espresso machine to a Lelit Bianca for £2000

Then I bought an EG-1 grinder for £3000

Now I'm looking to upgrade my machine soon.

Also I bought acaia scales and a puqpress and various coffee related things along the way, as well as spending essentially £10 a week on beans

Magic the Gathering

For me, it's board games. I figured a few good board games could last a while. I'm sure you are (incorrectly) guessing the next step, that I just bought too many.

No, I bought Kingdom Death: Monster. And now I want the expansion packs, which combine to nearly $3000.

Traditional painting and illustration! While I now know that I never needed to spend more than $250 for professional-grade tools, I've spent about $18,000. As for sales in 3.5 years, they don't account for more than $800. For that I mostly blame Instagram where it's not possible to grow anymore organically and get an audience & potential customers. So I moved to the federated open source PixelFed now, if anyone's interested in my book-style illustration: https://pixelfed.social/EugeniaLoli

Also, as a word of advice for anyone who wants to also do illustration and don't want to do the same mistakes that I did. All you need is:

• The Lukas 24 watercolor palette of student grade ($18). It's good enough and these days most paintings are scanned, so even if not all colors are lightfast, it's not a big deal. Few people only buy originals, most go for prints. If you're going to go selling originals, consider the Daniel Smith primaries set of 6 colors for $40.
• A set of brushes of different sizes, including a flat brush and round brushes including a long thin one to do details, $15
• Pencil, eraser, sharpener, $15
• A set of gouache. Best bang for the buck for professional quality is DaVinci brand ($10 per large tube), or if you want to go cheap, the Himi Miya set for $25. If you go for the cheaper stuff, it's still advised to get a better quality white tube, so it's truly opaque (the cheap stuff aren't opaque enough). So go for Holbein or DaVinci white for $10-$15.
• Soft core colored pencils, set of 48+. $15 (you will mostly need the muted colors to enhance the painting with harder edges)
• Grey, sepia, black ink pens, and manga ink brush pens (for some types of paintings only), $40
• 100% cotton paper for watercolor $25, or any watercolor paper for gouache $10 (gouache works on any, watercolor is more nuanced).
• Brush watercolor markers, e.g. Tombows or Ecoline -- in case you want to do such type of illustration too, $30 for a few muted colors.
• Masking fluid for watercolors, $10
• White gel pen and white Posca pen (0.7mm) for white highlights, $15
• Faber Castell white pencil soft pastel, $4
• Caran d'ache Luminance white colored pencil, $4 (the cheaper colored pencils above again don't include a strong white)
• Caran d'ache Neocolor II white crayon, $4
• A ruler, to help you sketch.

I included various mediums above in white color because highlights are king in illustration, and each provides a different look and feel, depending on the painting. Happy painting!

Getting fed up strimming our 4 acre, very steep field.

I looked at remote control mowers. At the time they were all well over £6k, so I thought I'd try building one. Well, I've done it and it works well, but it's taken three years and cost over a grand so far in parts.

Data hoarding and self-hosting every service under the sun.

Playing racing games on PC.

At first, it's just a few racing games with an Xbox controller.

Then it get more complicated with the more advanced racing sim/arcade and the controller isn't enough anymore.

Then come a simple wheel and pedals set.

But now the games is way more enjoyable, then up the difficulty.

Now I need gear shifter, hand brake, better monitor, better PC.

Then not long until I need a full racing cockpit to mount everything on.

And now, after all that is just the beginning.

Surprised there’s no reef tank people here. Imagine spending $5000 on a 20 gallon fish tank - BEFORE spending any money on corals.

Ya it CAN be done for $50, but nobody does that.

Homelab (running home servers). Especially since I'm in Canada so I pay out the ass for shipping. Got into it purely out of interest for server administration, programming (computer science in general really) and the desire to experiment on my own hardware, but I'll have you know I have a total of 48 processing cores and 30 TB of storage running my personal fileserver and "private cloud!" Though not relying on the likes of Google for data storage and "cloud" services is a massive genuine benefit!

I also run BOINC and Folding@Home on the excess computing power in the winter, essentially "donating" it to science, which is perfect because my house only has electric baseboard heating anyway so I'm consuming the same amount of electricity for heating either way, and the electricity sources are mostly renewables where I live! The home office is toasty all winter, if kind of loud.

Tinkering with electronics. Like, breadboards, integrated circuits, transistors, microcontrollers.

I've got a tacklebox full to bursting with components and parts worth probably close to a grand.

Smoking cigars was a huge money suck, back when I used to smoke.

Other than that and video games, it's got to be art and writing supplies. Probably over $1000 if I add it all up over the years.

Which actually isn't that bad considering how much I enjoy writing and drawing, so I guess that's something to be happy about

I’m not sure it can get worse than bird watching. Completely free to start. Then you are like “man I wish I could see that bird over there” so you buy some binoculars. Then you think “dang this bird is moving too fast I still can’t identify it, maybe I should try photographing it”. Two months later you’ve spent 10k because bird photography is apparently the most intense kind of photography. Turns out photographing very tiny things that move very fast from very far away is very difficult and the lenses you need start at thousands of dollars and go up to tens of thousands of dollars. That isn’t including the camera body, which you probably want very fast autofocus on, along with bird eye tracking, which hardly comes on any cameras at all.

Yeah…

D&D. When I got back into it as an adult it was mostly because I could get into it for $0. I was dead broke at the time. I ~~pirated the books~~ downloaded the free basic rules 😉 on my trash find laptop and was good to go.

But man once I had money it turns out I really like collecting books and the D&D ones are not cheap. I do not want to think about how much I've spent.

Making electronic music. You can get lots of software tools for free, so I started out with those.

Then I realized how many details get lost, depending on what speaker/headphones you use, so bought myself higher quality headphones. As in, quite high-end for normies, but obviously, I'm at the lower end for music production hardware.

Now I'm considering buying a MIDI keyboard, because those software tools don't quite emulate proper piano playing. Although, you could obviously also spend money on getting different software tools. And of course, on a quadrillion plugins for these software tools, to produce different sounds.

I'm just glad that my other hobby is programming, so when my music-self gets excited about an idea, my programming-self will want to solve it.
...and then never finish what music-self wanted, but at least we're distracted from spending money.

Reloading.

I thought, I can buy a Hornady press, use range brass, and same some cash!

And, well, kind of. But mostly no. Yes, buying primers, bullets, and powder, and using range brass is indeed cheaper than buying boxes or cases of ammunition on a per bullet basis. Sure, a set of dies can get expensive ($200+ for match-grade dies if you do, e.g. long range shooting competitions). Oh, and you need to clean your brass, preferably in a wet tumbler, and then dry your brass, and also get a trim station to trim to length, and possibly a primer pocket swager if you've picked up military brass with crimped primer pockets... And a scale, you gotta have a good scale so that you know exactly how much powder you're using (seriously; you need a good scale, you cannot skip this), and you need a chronography to measure speeds to develop the most accurate loads...

...And then you start getting into progressive reloading presses that are intended for really high volume shooting that start at around $2000, and top out at around $10k, plus things like annealing stations so that your neck tension is always consistent after you've crimped the case, and powder tricklers for when volumetric powder dispensers aren't accurate enough...

But the real expense hits when you're shooting 10x as much because now ammunition is "cheap".

BRB, gonna spend $400 on 8# of Varget powder and $300 on 1000 Hornady ELD-M .224 bullets.

3d printing.

Started out with a cheap printer, mostly to supply my friends with miniatures and terrain. They loved the stuff I printed for them, so gave me money for my effort, which went into upgrading my printer and buying more supplies and buying a new printer so I could print better, bigger things for them.

Then, so enamored by what 3d printing could do, they bought their own 3d printers.

and now no one talks to me cause I no longer have any use and i'm stuck with a printer I havent even removed from the box and assembled for 3 years, and another printer that only stays around because every 2-3 months something comes up where I can design and print a part to fix something around the house.

3D modelling. It's impossible to get into 3D modelling and not get eventually sucked into 3D Printing... Which as other people have explained on the thread, is it's own money sinker.

Literally any hobby I have seriously messed with.

Although- racecars was never cheap.

My homelab started off pretty cheap. But, at this point, I am quite certain I have a few thousand bucks worth of hardware. Shit- I have two thousand bucks in just HDDs, SSDs/NVMes...

Pc gaming. I started off with a refurbished HP omen, but now I'm wanting something more. I'm aiming for a custom built and that has led me to the discovery of companies like Digital Storm, System 76, and Falcon Northwest.

Torrenting and data hoarding are also hobbies of mine. Every so often I'll buy an external hard drive once I max out the storage on a current one. One hard drive failed a while back and now I'm looking for data recovery companies, but their services are a bit pricey.

My humble used office desktop turned NAS quickly became a dual-processor, 64GB ECC machine with more storage and processing power than I'll probably ever need.

Probably gardening.

A few seed packets and some dirt turns into building nice cedar raised gardens, filling them all with great quality soil, expensive liquid fertilizers, various irrigation systems, and so on. And I can't just haul all that dirt in my sedan... But hey, I have 20+ tomato plants, and about as many different pepper plants every year.

It's honestly nowheer near as expensive as some of my other hobbies, but on the "a lot more money than I expected" scale it's up there.

Started out with a raspberry pi several years ago. Got my feet wet with entry level, beginner friendly NAS prebuilds. Hunted for recycled computer parts. Now searching for and actively acquiring enterprise gear that is making a massive dent in my wallet.

Knitting. Only handdyed yarns, which are costly. And of course you need ALL colours. And only the most luscious fibres and yarns.

I've resorted to dyeing yarn myself - which opened up another deep, deep rabbit hole.

And a business.

I think audio, headphones, amps, all this stuff. Microphones, recorders, physical mixing gear. If I would go in that direction, I would need a seperate room and loots of money

Amongst all my hobbies (am kind of a serial hobbyist…) I think fishing is the one that turns out the most expensive compared to my initial assumption.

Started with trout fishing into fly fishing the lure then carp… daaamn now I’m looking into a bassboat or a kayak…

Music production. Started with a old pc and a pirated version of ableton. Now I bought my first top tier laptop and a license of ableton… and oh whats that around the corner? Is that a modular synth?

Vinyl records... 25 years ago you could hardly buy them . I listen to punk and they never gave up on the format and so it was cheap and collectible because print runs were small.. from 2010 onwards, they came back in fashion and the major labels started clogging up the pressing plants and then pre-orders became a thing and the price started creeping up...now, in my country a vinyl that used to be $20 is now pushing $55 and mainstream artists are pushing $70 ...my desire has really waned.. I'm priced out of finding new artists because I can't buy everything all the time like I used to.

Film photography. Started with a camera I got for free, and $20 worth of film. Quickly spiraled into many cameras that I bought or inherited, and so much money on film and development

I started music when I was like 7/8, my parents encouraged me to do so. And here we are, 20 years later, my dad told me cocaine would’ve probably been way cheaper.

It’s a toss up between cooking and home networking for me.

Cooking because it started off as just finding neat recipes and giving them a shot to now experimenting with new techniques and harder to procure ingredients. My pantry looks like a mini spice market and keeping them fresh is its own hassle. Plus needing all the gear gets expensive!

I also got really into home networking during the start of the pandemic. I went from having a simple off the shelf mesh network to a full network rack in my basement serving some high end access points and cat6 drops in every room. Now I have a pretty secure iot stack that’s separate from my main vlan and one devoted to my work computer.

No other ham radio nerds here besides me? It always starts with a $35 Baofeng hand-held...

Running. Not as expensive as a lot of the things posted about here, but my shoes cost ~$150 and I have replaced them a couple times a year. I'm planning to get in to trail running soon (as opposed to running circles in my neighborhood, so now I want to add a running vest and a GPS watch, which is not cheap.

Considering that in theory all you need to run is your body and an open space, I feel like I have spent a lot of money.

EDIT: I forgot the ~$140 bone conducting headphones I bought! I for sure feel safer with them than my old headphones though, since I have been doing almost all of my running till now on the road.

Arma 3. I updated my router, computer and bought the dlcs so I could run a server.

Flight-simming. I started with a cheap joystick. Now my desk is littered with touch-screens, custom controllers etc.

I've had amazing luck with hobbys that should be expensive, but weren't.

Me & some friends have a small computer museum. We collect minicomputers & workstations. (Stuff used in science & academia.) We have computers dating back to the early 60s. But we started in the mid 90s, when NO ONE was interested. So we got everything for free. (Well... for the cost of renting large trucks.)

I'm a photographer. My DSLR is old, from just when DSLR's were getting "good enough" at a reasonable price. I bought it used when it was already "obsolete". And then someone gave me an exotic industrial camera they had at work which was "broken". It was too broken for industrial use, but works fine for studio use. I had to build some hardware & write all the software to use it, but... the results are fantastic. It blows away my DSLR. (But uses the same lenses!)

My library has probably cost a lot, but that's spread out over 40 years, so I don't notice it. (Also, I worked in a used bookstore for a bit, and that's a good way to get a lot of books CHEEEEEEEAP. Employee discount? Yes. Discount on books in the back that are slightly damaged and unsellable? YES.) And I've occasionally sold a rare book, so that offsets things.

Etc.

(Note: my home computer collection spans ten full-height racks. A few of those are on loan from the museum, but most are mine. Spent close to nothing on that. Somehow.)

I had a recipe blog prior to the pandemic. I put well over five grand into it over four years and didn't make a cent.
If I hadn't decided that I hate website with ads and third party cookies on them I probably could have made a few bucks during the pandemic.