As Joe says, give it to the next highest bidder - seems the easiest way to go. If by 'add-ons' you mean you also tried your luck at selling him something extra to what he bidded on maybe he just thought 'sod that'. Auctioning something by PM is always a risky business.
yes. i think it's closed because has three possible: 1.hightest bidder is winner! 2. sold at bin by pm!(because many buyer dont want let other know ) 3.has other Special circumstances. thanks