Generally speaking, artists get paid best. In part this is due to the nature of how games are initially seen, understood, and promoted: visually. Art is the quickest of all the skills to evaluate and the easiest to judge. Online, you can see art by accident. You can't really do the same with writing, code, editing, or music. In short, finding an artist is probably easier than finding any other skilled person because you can process a larger number of them in a given period of time. The result for artists is that they're seen by more people simply due to the nature of their medium.
I think the big problem though is that creators aren't educating clients on what they're doing. If people think that putting quote marks around their dialogue in Ren'Py is on par with creating a battle engine, who's fault is that really? If you have no understanding of programming it's impossible to evaluate. It's the programmer's responsibility to communicate what they're doing and how much work is involved. Otherwise their service is a blackbox—money goes in, code comes out, and who knows what happens in the middle.
I haven't looked in the recruitment sub-forum recently so this mightn't still be the case, but I've noticed in the past programmers wouldn't share any examples of their code. So:
- Write a piece of code that does something Ren'Py doesn't by default.
- Demonstrate the functionality with a video.
- Share the well-commented code and accept that people can steal it. Make the code look nice too. Maybe take a screenshot of it in your editor with pretty syntax highlighting. You're now leveraging some of the immediacy of art to advertise your non-art service.
- Show how to integrate it into a Ren'Py project.
Encouragement without education doesn't help the artists (or musicians, editors, etc.) understand why things are as they are. Most folk seem to think it's a problem with cheap clients trying to rip people off or that there's just not enough demand for X. For the first one I think the saying "never assume malice where ignorance will suffice" applies. I think most clients are well-meaning. As for demand... yes there are many things outside your control but there's also many things inside of your control. You are, for example, in control of where, how, and what you advertise. Here's a checklist I wrote of things you're in control of when advertising your services. I think demand is determined by circumstances and the creator—you can create demand for an entire class of service if you do it well.