I know the place you're talking of. Those bottles are not authentic. As with all the stuff sold on the street of NYC, if it's got a brand telling you the price is too good to be true, then it probably is. Or, in a best case scenario (for you at least), it fell off a truck.
On the other hand, if it smells right, why not? My ex works in the shoe import business, and, without saying too much, let's just say that even the merchandise you buy in reputable stores can be less than authentic. (Although the quality is often the same.)