If it is at all realistic for you to have a professional remove your facial hair, you should do so.
There are a few problems with diy laser hair removal. The big one is that you have to be paying close attention to laser placement to actually get complete coverage of the area, and it's really hard to do that by yourself especially while experiencing a bunch of painful laser blasts. If you fuck this up and aim at your own eyes, you could blind yourself.
Another problem is that any machine you could afford is going to be less powerful than commercial lasers like what you find in salons, and it will have a smaller laser "spot" - these mean longer sessions and slower progress.
Compounding all this is the fact that some home lasers don't even have a means for cooling your skin, which means that despite being less effective, a home laser will probably be more painful, and again, you don't just have to bear the pain, you have to focus on what you're doing while experiencing the pain, for longer than it would be if someone else was doing it.
TLDR: hair removal is not like hormones, DIY is simply unreasonable.
Addition: IPL is not powerful enough for facial hair removal; waste of your time and money. The cheapest machine that's at all useful is the tria 4x, and I don't recommend it for all of the above reasons.
