I sold BTC on ebay for a little bit and made some money, but I did get scammed a few times.  Additionally, PayPal will side with the buyer.  Also, like others have said above, eBay requires some sort of physical tangible item.  I was told by eBay that if I wanted to sell something that had no physical tangible item to be sent that I had to post it as a classified in "Everything Else>Informational" or something very similar to that.  If you post in that, from what I remember, eBay will charge you $9.95 for a 30 day listing.  I guess if you can sell enough BTC to cover that+eBay and PayPal fee's then it could be a way for you to do it.  Like others have said, it is prone to being scammed.  The best way I can think to do it is to list it on the classifieds area, then have them email you through the email that is attached to their PayPal account that they use to pay for the BTC and then send a paper wallet.  It is a hassle, and it may not even be that profitable.  At first when I started selling I was making between $2 to $4 dollars profit after fees.  However, with the setup I just mentioned your profit goes down close to a dollar or less due to the postage/envelope/ink/paper and whatever else you would need along with all the fees. 

I hope that gives you some sort of idea what kind of a hassle it is and what you can do to safely sell on eBay.

The way I outlined it up there probably isn't the best way, but that is what I would do.