Benjamin Bernstein and Benjamin Stokes of Red Sky Capital LLC invested $3.9 million, or about $243,750 per unit, in a 16-unit multifamily building in Brooklyn. The 759 Manhattan Ave. property was not on the market. Previous owners, Arlene Semaya and Helen Resnick of HR (1998) Investment LP, were approached to sell the five-story 1930s building, which is both rent stabilized and primarily rent controlled, by the two entrepreneurs.