I have been doing manips quite a bit recently and have quite a few pieces but have no idea what price I would want to sell them for. Sure i could just auction them but I always find Auctions confusing or easy to forget about.

played around a lot with the mane and tail on this one, it one of my favorites

so incredibly happy with my rumble piece too but I can't share it XP

I'd say maybe somewhere in the range of 10-25k. Your manes and tails are very nice, especially in the second piece, but especially on the first piece, the lighting of the horse doesn't match the lighting of the background, and the grounding could use a little work too.

Another way to find out how much to sell your art for is to auction a piece and see how much people are willing to pay for it.