Do you know how do international auction houses earn their fee? They earn a fee called premium fee which the buyer will pay on top of the successful auction price. This premium fee could be substantial. Searching online, I found an article in theartnewspaper.com
“As of 20 May, buyers at Sotheby’s will pay a 20% premium on any hammer price up to $6m, plus 10% on any portion of the hammer price above that amount. The company’s contentious 1% “overhead premium” will be scrapped.”