The buyers drive the price.
Ebay fees once a sale goes over 25 dollars isn't that much of an issue.
What kills me on Ebay is shipping to other countries. I used to flat fee but after getting burned on shipping a couple of times I ask international buyers to contact me.
Eventually an obviously over priced item will sell but collectors and even casual hobbyist know if they're getting gouged or not.
I've found games going for over 80 dollars for half as much just by trying different search terms.
Lots of sellers have no idea what they have.
Sentimental value will have people overpay probably more than anything else.