Just tried to sell my first bitcoins on ebay, and the auction went really well with lots of action and a good final price, but now the buyer will not pay for the bitcoins he won!
Anyone else dealing with this?
It seems like my buyer at least is using ebay to buy bitcoin options at no risk. Since the tank, he has had no reason to pay up

Since the buyer committed to buy your item he will either pay for it or be penalized by Ebay. I believe 'no payment' issue is pretty common at Ebay, it doesn't matter what exactly you are selling.