I sell pre-loved shoes on eBay all the time. But I'm not very hard on my shoes (especially work shoes) because I don't wear them outside. I change into tennies to go outside. So when I do sell them, they're in excellent condition.
I have found, though, that well recognized brands sell best, and if you did pay full price, don't expect anywhere near what you paid for them. Usually I sell Pradas for about $50 and Manolo Blahniks for $100.