Sellers can open an Unpaid Item Dispute 4 full days after listing end.
They can then close it 4 full days after opening the dispute, if no payment has been made. Closing the dispute issues a strike to the non-payer, credits back the final value fee to the seller, and allows the seller to relist.
4 full days and 1 minute and no $$$, they get an unpaid alert from Ebay. Set it up that way. Personally, I hate bidders that bid w/o money. When I go to the mall, I bring my money or my credit card. That is the way Ebay should be. After the alert, wait for 4 days , 1 minute from when the auction ended and make it a permanent strike. Relist it after the 8 days.
Block them so that they do not re-bid.