NEW YORK CITY — IAC, a holding company of media and digital assets whose brands include The Daily Beast and Investopedia, has acquired the land on which its 10-story headquarters office at 555 West 18th St. in Manhattan is situated. The sales price was $80 million. Designed by architect Frank Gehry, the building was completed in 2007. Eric Michael Anton and Steven Siegel of Institutional Property Advisors, a division of Marcus & Millichap, brokered the deal. The name of the entity that sold the land was not disclosed.