If they back out after bidding, there's
nothing you can do except file a non-paying bidder alert on E-Bay. I had
this happen to me. Still, it generated a sales contract, something a broker
couldn't do in a year. This is the future in boat sales.

Sounds like it was exactly the same results your broker got the previous year.
No actual buyer came forward.

Some 12-year old kid cold have placed that bid on E-bay.