I buy EVERYTHING on ebay, it's an amazing resource. Selling is less pleasant, and I've been burned a few times, but I make EVERY EFFORT to be reasonable. Shipping is always an issue, I am not willing to go to the post office multiple times.
I try to keep mine clean, and I am hesitant to be a black spot on someone else's, so I like to talk and be sure everything is RIGHT before we leave it...