As long as they want .... lol ... sellers at the mercy of ebay feedback policy... I had one buyer give me negative feedback cause they reckon they never recieved item... but they never notified me that they did not recieved item even though Aust post stated different. It was also a pitty as I would have sent the a second one. 

Ebay doesnt care bout sellers so be carefull we are at the mercy of buyers.