A  version of this article originally appeared in  The Back Room ,  our lively recap funneling only the week’s must-know art industry intel into a nimble read you’ll actually enjoy. Artnet News Pro members get exclusive access— subscribe now  to receive the newsletter in your inbox every Friday. There has been quite a bit of ink spilled over Sotheby’s in the last few days, with everyone trying to make sense of its finances. Let’s recap. A New York real estate broker just hit the auction house with a lawsuit , alleging that it’s owed a $10.2 million commission over the sale of its longtime Manhattan headquarters. (Sotheby’s disputes this.) Meanwhile, over at its new Breuer Building outpost, a swanky new restaurant, Marcel , just opened. To boot, a delayed-payment program has come to light, which rewards sellers with 7 percent interest if they hold off on cashing out for six months.…