While it is slim picking there, they do have the right to ask for what they want, especially in the unpaid section.
As for the paid section, I think small budgets, misunderstanding, and the fact that pixel art is a dying art are too blame for unreasonable prices. There's a lot of work on the pixel level that goes ( consciously at least) unnoticed. It's easy to think that with all the limitations, that pixel art is easy to do.
Also, rarely ever do professionals come to the job forums. Usually it is someone wanting to make their naruto mmorpg, or at best an indie platformer. These people usually offer up what they have in their pocket to artists; with good intention, but the time/money scale balance is often seriously warped.