Ebay's so iffy.
I am quite happy with their offspring, half.com, though. Check it out sometime, if you haven't. Selling's great through it, no charge unless you sell, postings stay up until they sell or you take it down, and a pretty simple item condition rating system - but limited items - books, movies, music, and videogames/systems.

It's AWESOME for textbooks, I'd recommend it to every student everywhere.