Don't underestimate the devs. It's a huge market with less competition (that's why suggested npm too). One of my sites makes very good money for doing something very trivial, something that almost every dev can do if they spent like 5 days on it, yet I have people paying $47 / mo for over 3 years just because I give them a super easy way to do it with an API.
Most devs generally have good budget or power to make purchases under $50 / mo without consulting their manager and also you're mostly dealing with very nice people.
The only issue I've ever faced when dealing with devs (and it could be just my own myopia) is that they are most often perfectionist. So whatever service you provide, better make sure it's the absolute best of the best - which it should be anyways.
