Ya something is suspicious with this guy. He emailed me to my registered email not my ebay inbox. He literally contacted me within 3 minutes of paying. He registered in 2007 and has no buying or selling history besides the -1 buy 7 years ago.
I'd call Ebay and tell them what's going on and what just happened to you. Just cancel the sale, and refund the money on the basis of "Item listing error (item wasn't suppose to sell to someone with less than 5+ rep" "Ran out of stock" "user is harrassing" "buyer changed their mind / wants to cancel" blah blah blah.... Find one, and let him know he has to wait a few business days for the refund to clear.
Trust me, this guy isn't worth all the problems you could get into. Even if you shipped it, he'd probably claim the item broke or you shipped him the wrong one.