One more quick point - there are a lot of dodgy internet retailers in the US - in particular those selling photo/video equipment - and a lot seem NY-based. If you buy online stick to someone reputable. I've used
B&H several times in the past, and they are highly regarded. They do Internet sales and have a store in NYC which offers the same prices. Others like Adorama are also good.
There are also lots of dodgy retailers in places like Times Square in New York that prey on European and Asian tourists - avoid those like the plague. They'll offer you a ridiculously low price - then once you've got the camera will tell you you have to buy things like the charger, battery, cables (which come included) separately, or the 'fantastic price just for you Mr' - will be full retail anyway.
Places like Circuit City, Ritz Camera, Best Buy - are fine - but you'll typically pay 'full retail' - which is less than the UK price, but not as good as an online (B&H) type price.
Amazon is usually somewhere in the middle price-wise.
So - looking at the price for the camera you suggested:
Retail : $599.99 / £316
Amazon : $479.94 (prob free shipping) / £253
B&H : $449.95 (prob $10 shipping) / £237
B&H PAL model : $579.95 / £305
PIXMANIA by comparison : £348 (if you are intent on the PAL model, probably get here, if you are OK with NTSC get there)
Beware also - local sales taxes in the US. Unlike the UK where the price advertised includes VAT - there sales tax is additional. The rate depends on the state you are. Online purchases (from out of state) do not attract sales tax (unless the vendor has operations in that state - complicated).
So - if for example you are going to Florida, and have a camcorder delivered to your hotel, from B&H in NY- no tax - but then you have to pay shipping. Do the maths and figure out what's best.