The New Meaning of "Or Best Offer"

[Windsong]

I just bid a ridiculously low price for a rather rare clarinet on Fleabay, where the price was listed as "$xx.xx, OBO".  I offered the full asking price, but admittedly, the auction looked odd to me, since it did not say "Buy It Now, OBO". 

So this is Fleabay's new clickbait, I guess.  Their new definition of or Best Offer is truly literal; I can offer 40 bucks, but the auction does not end. If someone else offers $400.00 on top of my offer, that is now the "Best Offer", and so on, until the clock runs out. 

Caveat Emptor, folks.