A group that is easier to conclusively identify than gay couples
This is very much a regional thing.
I went to several auctions in Southern California where a $100 refundable deposit was required to get a bidding number; one of those had a cash only (no checks, no cards) policy for end-of-auction payment as well.
That sort of thing is unheard of in these parts. For that matter, I've never had an auctioneer in Wisconsin turn down an in-state check with ID, even when their ad says otherwise. And, as I recall, some of the auctioneers down in Oklahoma even took my out-of-state checks.