Maybe it's the trouble of skinning them and tanning them ?
probably........and marketing them. Around here one would be lucky to get $20-$25 bucks from a fur buyer for a raw hide in it's prime with little damage from gunshots. Most folks render them worthless if they do not know how to skin them properly. Take the whole animal to the buyer and he may give you $15. Then the buyer needs to sell it to for a profit. This low cost is why many get left in the field. I know several yote hunters that can skin a yote in the woods from a tree or a fencepost in ten minutes. It's not a get rich quick proposition, but it does help pay for gas and ammo.
I have sent several Coyote skins in to be tanned. These are hides which were properly skinned but not fleshed. I believe the cost for tanning and fleshing was around $60 plus $20 shipping. This did not include the cost of me shipping the frozen hide to the tanner. I think it took 3-4 months to get my hides back. So you see, $75 is a pretty good price if the hide is in good shape and you want one. My hides were tanned for clothing and were just a loose fur similar to your E-bay link. They were not made into clothing, but were given away and used as decorative items.