Pilot training
An expensive condition not mentioned, presumably because Vultures cannot imagine anybody unable to fly, is pilot re-training.
Many airlines bought the Max on the strict condition that no expensive and timewasting pilot retraining would be necessary, it was one of the Max's big selling points.
Boeing's own internal recommendation, certain to be endorsed by the FAA, is for proper simulator-based retraining to be introduced. A lot of airlines will then demand compensation for being sold a product under false pretences, in some cases written into the purchase contract. I wouldn't mind betting that some will use it as a loophole for cancelling a purchase they can no longer afford.
Biting the hand that feeds IT
