For a group with a $330 million annual operating budget, $55 million—a valuation made by Sotheby’s—is a lot of money, but the sudden announcement caught opera fans by surprise. That is because, in September, the Met announced a multiyear $200 million deal with Saudi Arabia that would have the company perform there each winter and was meant to greatly alleviate its capital woes, the most worrying aspect of which has been the drawdown from its endowment.