An unknown buyer has paid $11.77 million for Unit 9B at 15 Central Park West, according to city records. The same buyer purchased a $720,000 "suite"--the euphemism for staff accomodations at the building--on Feb. 22. Though we couldn't confirm the identity of the buyer, one of the names listed on the deed was Queens College graduate Betty Lau, the CEO of technology firm Applied Info. Partners.