This according to a study done by Priceonomics, the self-described "price guide for everything." Know what they base all of this evidence on? The purchase of fixed gear bikes. Manhattan sells more than Brooklyn, apparently.
I wonder if they considered the fact that Manhattan is mostly flat while Brooklyn is peppered with mountainous hills. This is why I own a 10 speed. If I biked to Sunset Park on a fixie I'd probably die.