The typical asking rate per listing is in the $40's per square foot per year. The Flatbush region is going through a a boost in rates. In the last 3 months, the median rate increased $7 per sqft per year. That's a 19% rise in rent.
Compared to the rest of the New York City market, the Flatbush region has lower rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 4 listings have been posted online, which means new availabilities most likley are going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,000 sqft. Most properties in this region are close to 3 stories. Most buildings in this region were built in 1931 and are Class A.
Not much of the real estate is used for commercial space, so it might be hard to find office space. Wholesale trade is the dominant industry in this area. Commute by bike is the most popular way to get to work amongst Flatbush folk. Commuting between 30 and 45 minutes a day is the norm for those who opt to reside in this part of town.