Arik Lifshitz’s DSA Property Group is in contract to buy a 15-story dormitory building in the Financial District from Pace University for $51 million, sources told The Real Deal. The private university hired Newmark Grubb Knight Frank in March to market the 75,000-square-foot property at 106 Fulton Street, between Dutch and William streets. The building, which Pace converted into dorms in 1999, also has a Burger King on the ground floor.