From my limited experience thus far, most camera stores here tend to quote prices that are a little higher than what you usually find in Singapore (taking currency conversion rates into consideration). A lot of the low-value stuff (filters, bags and the like) is much cheaper in Singapore than here, but for anything of fairly high value (lenses, camera bodies, etc), I would say that the prices are pretty much on par. So don't expect to save much money when buying in the US.
However, one advantage that stores here do have is item availability; chances are that stuff that you may not be able to find in Singapore will be much easier to locate around here.
Like what mpenza said, though, a lot of the real bargains here are to be found online. If you're going to stay at the same location in the USA for several days, do consider buying stuff from B&H; their FedEx Saver shipments typically arrive within 3 days (excluding weekends and holidays). Adorama.com is a good site to look at as well. I've also had luck getting extremely good bargains on eBay, but that's definitely far less predictable.
However, I must reiterate that you may well get better prices at home in Singapore, so do your homework first. The prices listed on the B&H web site can be considered to be a gauge of what constitutes a "good" price here in the US, so use those for your comparison.
As a person with extensive experience with most camera markets here's my 2c worth.
USA (New York, B&H, Adorama)
Prices are unbeatable on Superteles, unusual primes and some professional zoom lenses. Consumer grade gear is often priced a bit cheaper than SG but when you factor in shipping the consumer grade equipment prices are similar.
Cheaper filter and accessory prices (up to 50% cheaper than NY) Cheaper for film SLR bodies in most cases (especially Nikon). Shipping costs to non SG addresses slightly lower than New York based businesses.
The main difference however is in stock levels and professionalism.
The stock levels held by both B&H and Adorama are staggering to behold. Thousands of line items and most in stock at any one time. Really unusual items if not in stock can be ordered quite quickly.
B&H and Adorama don't screw you around with different prices on different days / salemen/women type routines. There's one price and it's non negotiable. However their sales reps are quite 'off hand' and often appear curt to the point of rudeness, though to be fair this is typical of NY sales people.