While there are good shops in Brooklyn, there are several about which you should beware.

B&H Photo is reputable and honest. I know people who have dealt with them without trouble.

SOme of the Brooklyn shops use tactics similar to this:
You see an exceptionally low price for a hot new camera. You go to their website and place an order. You will receive an e-mail or phone call from them that they need to "verify" the order. When you call them back, you will get a high pressure salesman who will push all sorts of unnecessary extras upon you. For example, they may charge 4-5X the normal price for a memory card. Or, they will tell you that the regular battery is no good and you need an overpriced extra battery. Just check out the prices! One site I know that does this is Broadway Photo (www.bwayphoto.com), but lots of the Brooklyn places are shady. If you do not order anything extra, suddenly the camera will become backordered. They will make you keep waiting for weeks. And not all the cameras come with US warranty.

Just a few words of caution. If the price is super low, there's a reason. People in the past used to use ads from those places for price matching with Starwood, etc.. I am not sure if you can do that with the print ads in the back of photo magazines.

Best wishes.