Can I sell my chametz via eBAY? I have no expectation that I want to buy it back. I would pack it and ship it before Pesach, so it's definitely not in my posession during Pesach. Is this problematic as there is a "built-in" eBAY policy that the buyer may return any product that he is unhappy with?
The return policy through eBay purchases isn't substantially different than the "buyer's remorse" policy used by the majority of rabbanim for an ordinary mechiras chometz.
Potential issues would be as follows: