I guess he forgot about the "legally binding contract" part of the transaction.
Just for fun why not email him back and let him know that when he bidded on the item he is legally required to make payment (use ebay's own quote to help back it up) and then mention you have discussed the matter with your private lawyer who is willing to take this case to court to uphold the contract between you and the buyer.
Good thing Ebay has that mutual cancellation thing where they refund us and you can let the "fanatical" buyer go without giving him a strike. I have to admit even though it's rare, sometimes you do run into an unexpected problem and can't make the payment.
So yeah.. like Leo says at least he's trying.. now send off that letter threatining legal action against him!