A group including billionaire investor Bill Ackman paid $91.5 million for a duplex penthouse at Extell Development Co.’s One57 condominium tower, one of New York City’s most expensive home purchases ever.

The purchase of unit 75 in the luxury skyscraper overlooking Central Park closed on March 27, according to property records filed Thursday. The buyer was listed as 57157 Co. LLC, a single-purpose entity that Ackman controls.

The 13,554-square-foot (1,259-square-meter), six-bedroom home spans the 75th and 76th floors of the 90-story skyscraper. Ackman last year told the New York Times it was “the Mona Lisa of apartments.” Monthly common charges on the unit were estimated at $23,595, according to documents Extell filed with the state attorney general’s office.

The initial asking price for the home was $98.5 million, and it was last listed for sale at $115 million, according to the filings.

John Pinette, a spokesman for Ackman’s hedge-fund firm, Pershing Square Capital Management, declined to comment.

In December, a 10,923-square-foot duplex on the top two floors of One57 sold to an undisclosed buyer for $100.5 million, the record for the most expensive residential deal ever completed in Manhattan.

Better Deal

On a per-square-foot basis, Ackman’s group “got a better deal,” said Jonathan Miller, president of appraiser Miller Samuel Inc. and a Bloomberg View contributor. “His unit is much larger” than the more expensive sale.

The Ackman group’s price was about $6,750 a square foot, compared with about $9,200 paid by the buyer of the top-floor apartment, Miller said.

Under a state property-tax break applied to the building, Ackman’s group and all other owners at One57 will be paying reduced levies for a decade, Miller said. The burden on Ackman’s unit, with the abatement, is about $20,813 annually, Extell’s filings show. Without the break, the yearly bill could have been about $232,692, according to the documents. Unit owners will pay the full amount once the abatement period ends, Miller said.