$17.50 for 250g of single origin, high Q-score coffee is not unreasonable. You'll see some single origins at Flight Coffee go for $23 for 250g or so, and obviously very high Q-score coffee goes for significantly more. I don't usually buy 1kg lots of coffee due to freshness concerns.

Hummingbird claims to source speciality grade coffee but I have seen so many defects (both roast defects and defects in the green) when buying from them that I kind of don't believe them (or they're getting ripped off by their suppliers). You still can make tasty coffee with Hummingbird but I think the quality of raw ingredients and the skill of the people who roast the coffee is lower than basically all of the other roasters that are targeting the speciality NZ market (as opposed to the commodity coffee market).