If the General Motors Building fetches $3.5 billion, the city stands to receive $114.3 million in taxes. The mortgage recording tax for the building will likely total $22.4 million, based on a $2.1 billion mortgage for 60% of the building’s value. The building already has a $3.1 billion mortgage attached to it; the real property transfer tax would generate another $91.9 million.

With the acquisition price for the GM Building estimated at as much as $3.5 billion and credit so difficult to come by in the current market, buyers will have to put up about $1.25 billion in equity to finance the deal. Few buyers have that much cash at hand, so several developers and investors will have to create partnerships to generate enough equity.

Even though Mr. Macklowe is facing foreclosure on his properties and has defaulted on billions of dollars in loans, last year he spent nearly $60 million to acquire seven adjoining apartments at the newly refurbished Plaza in Midtown, according to public records.