I knew the STereo Xchange back in the day... Walls of used ARC preamps, the big ones, a Goldmund Reference set up for play, every variety of odd-ball speaker system, double Quads, big-ole Infinities, etc.
It used to be a mecca for used equipment, and while not bargain -basement priced, Dave was fair. As the store grew, it began to change, and it really isn't about the fringe, or cult audio there at all any more.
He does carry some good lines, and does have some knowledgeable folks (Izzy is good on the video stuff), but it is not a haven for hi-end bargain hunters as it once was.
The best retail 'hi-end' analog type guy I have spoken with in NY since my re-entry into this stuff after a 10 year hiatus, is Josh (I think that's his name) at Highwater Sound. Cool products, great attitude. Alot of the other dealers act like they are doing you a favor.