how long to wait to file unpaid item claim on ebay?

A buyer purchased 2 buy it now items on 7/4 and has yet to pay. I don't get it if you are buying it now why not pay for it now. I have sent invoices but not response. How ling do I wait or what

2 weeks + several attempts to make contact is ample time and opportunity for the buyer to pay. I'd go ahead and file it as unpaid now; you've done all you can.