For its part, the Modern had arranged to expand into floors of an 82-story tower by Jean Nouvel to rise west of the folk museum, on a plot the Modern sold to Hines, the Houston developer.
To raise some of the money for these purchases, the Modern sold several artworks from its collection, among them a rare 1909 Cubist landscape by Picasso that many experts say the museum should never have parted with.
At Sotheby's, Mr Ai's 100kg of handmade porcelain sunflower seeds (pictured here), a domestic echo of the artist's monumental installation in the Turbine Hall at Tate Modern, sold for €417,004 ($568,250) to an anonymous buyer on the phone to Gregoire Billault, a contemporary specialist based in Paris.
In 2001, a collection that included works by Braque, Miró, Schiele and other moderns sold for $54 million, with Bacon's 1979 triptych "Studies of the Human Body" fetching $8.5 million, then a record price for the artist.
A new modern version sells for about $950,000.
Modern selling tools are reshaping the way brands are born.
Like other museums, the Modern periodically sells, works from its collection to pay for new ones.
The eight-track album, "Tomorrow's Modern Boxes," sells for $6, about half the price of a major new release at Apple's iTunes Store.
A prediction: 2016: A really great modern painting sells for a fraction of that amount.
