Sold about 40 items on e-bay over the past 4 years thus not a volume seller but I have had a couple of non paying winners. All e-bay will do is put a flag against them if you notify them, a few occurences and they will be struck off. Achives nothing, they just re-join with a different name.

If you took them to court what would be the point, they are probably just messers and don't have the money in the first place or any intention of completing the sale. You just have to accept there are a small percentage of idiots out there who will do their best to try and spoil things for genuine bidders.

You either have to relist or give the 2nd bidder the opportunity to have the item.