Sorry to hear you are having difficulties with sport bidders. As suggested, fixed price with IPR will solve those problems. Then the buyer cannot remove the item from the marketplace without paying for it. Also, setting one's Buyer Requirements to the strictest levels can help block nonpayers from having access to all savvy sellers' listings who do the same.
One concern I have to admit, though, is it makes me nervous to see a long time seller be wary of new buyers and guest buyers in these recent months. This is because the pandemic is driving new shoppers to online purchasing in droves. If these newbies aren't welcomed into the eBay fold, they will be lost to other venues, and that is bad for all of us. So just wanted to say that no one can determine someone is a scammer, deadbeat, or sport bidder based on a feedback score alone.
Not saying the OP is doing this --my concern is that there are sellers out there who cancel bids and put low- to zero-feedback buyers on their block lists before the newbies have even been given a chance to prove themselves. Such practice can be bad for business. (Don't get me wrong, every seller has the right to decide who he wants to do business with, and the right to be prejudiced against all new buyers if he so chooses.)
What I hope, is that those sellers who do auctions keep in mind they may be blocking a new customer needlessly. It is better not to anticipate trouble before it actually happens, if it can be helped. Better to block actual deadbeats rather than legitimate new buyers. Deadbeats reveal themselves soon enough, be they new or old, with feedback or without. (And there are plenty of bad buyers with feedback.)
Ok, stepping off the soapbox now, with apologies to the OP.
