i have to say, that this stuff is pretty amazing, and the fact that you guys are willing to make it 2d is really good. i was accually just trying to talk to a company which ended up flopping cause they wouldnt lower themselves to 2d

im currently building a top-down action rpg with gml and my on problem is finding good sprites. as with most of the people on this topic i agree that if you made these into 2d, alone, we cant really do much with a single image (itd look kinda weird to have a really good image, just floating around with a bunch of other one, and some random person calling that a game

). but if you took them and for instance made the knight character top-down, and made sprites that would make him move up down left and right, attacking and then getting hit, that right there is a huge peice that is much sought after for games, and most games take forever because of that alone. if you made a pack with an image you created one by one, with the animations for it like that, you could earn an easy 10-20 from each pack, or make a game pack of a bunch of them stuck together, that would be really powerful for any game and youd get many buyers.
that said, what Chessmasterriley said is very true and the originality of the sprites is what makes them worth the money
(if all games looked like mario itd be annoying

). how to fix that problem though is a bit harder. what would be good is with the level of skill that you have, if your willing to do this, id suggest selling out services. have a couple good packs definitly, but you could also have requests come in, you make what they need (and since very few people are good at 3d here itll be mostly 2d, which shouldnt be as hard) and depending on what they ask you make a price, maybe have a system of how you price sprites you make for a game.
also about the people not being able to pay due to lack of money, you could set up a deal with them and get a certain percentage of the games earnings (obviously this only works if they plan on selling it) depending on how much you do for them, which with how good the game would become with your amazing sprites you could earn allot off of that as well.
sry if im rambling a ton but those are my ideas to help out.
hope all that mess of info helped