Oh one more thing that might be interesting to know is the "irrevocable bid," which came into existence at auction houses after 2008. Basically a lot will come to market with a little star next to it saying a third party has already put down a particular bid for the work which would guarantee the sale, with an agreement that they'll get a cut of whatever the final hammer price is if someone else ends up winning. In practice, this means that the third party has already bought the work for their price, and the auction is just for show. It's a way for auction houses to secure better inventory from consignors ("we already have a buyer"), and allows buyers to avoid the hassle of bidding, all while putting on the theatre that this is a legit auction. Basically everyone hates it because it obfuscates everything, artificially inflates the market in a super obvious way, and is kinda dumb.