It depends on the project, I think. If you require hundreds of pieces to make the concept work (and such concepts have floated in my mind) even hiring an amateur would get pretty expensive. If it’s just small scope art (and for most games it will be) I agree, it can be relatively cheap. Though I’m still privileged in being able to afford that, some people couldn’t even really spare 200€ for a project that, statistically, is unlikely to make even half of that back.