The Sheepshead Bay neighborhood in Brooklyn is seeing growth in its retail and commercial markets. As immigrants from Russia, Turkey, Greece and the Middle East flooded to the neighborhood over the past decade ending 2007, jobs in the area increased 53 percent, according to Center for an Urban Future. Brokers say low rents are a draw for many companies — retail space goes for $30 to $50 a square foot in the area. White Plains-based developer Arcadia Realty Trust bought a two-acre site in Sheepshead Bay last November for $20 million with plans to build a mixed-use project with 300,000 square feet of retail space.