Why did you send it before he paid for it? Never, ever do that! As mentioned, there's nothing you can do if they don't pay. Hopefully they are honest, but if they are ignoring your emails, they'll ignore any requests to pay. The best you can hope for is to open an unpaid item dispute and close it 4 days later. At least you can get your fees back. If they don't pay they'll get a strike on their account.
Also, just so you are aware, you are posting on the Ebay Australia boards, you might be lucky and they buyer MIGHT pay, but if the item was being sent from Cyprus,it may take a while for them to get it and 'remember' they need to pay
