What I do find happens on ebay. If I'm bidding for something and it looks like I'm going to get it cheap. The auction disappears. Now if you have a minimum price then set it. Don't advertise as no minimum then withdraw because it's looking to go for a bargain, once in the auction that should be that, no I'm listing it elsewhere and reserve the right to withdraw. It's supposed to be an auction !
I hardly ever use Ebay these days, selling is a nightmare and buying is no guarantee you will get what you bid for.