condyk, have a look at kerso's prices, anyone that says there is no difference between US and UK prices is living in a dream.....so waste your money if you must.... US warranies generaly although not advertised will hold up worldwide.
I was one of Ian's very first customers, have bought many items from him over the last 2-3 years and I usually ask him to quote for new stuff. I just ordered another 17-40mm off him in fact. The reality is that he isn't always cheapest even against UK stock, but he is usually best option when there are Canon cashbacks around.
I don't need to be told I'm livin' in a dream either thanks mate. But let's unpick your confident assertion ... lets take the three recent pricing examples I gave above and see if your argument holds any water in the real world. I'll use B&H prices as easy for you to check too:
Sigma 17-70mm - $389.00 = £194.50, but then you must add local NYC tax when you buy, and VAT and Duty on import!
Canon 40D body only - 1,139.95 = £569.97, but then you must add local NYC tax when you buy, and VAT and Duty on import. Oh, don't forget there is £100 cash-back in the UK too just now!
Canon 24mm 2.8 - $305 = £152.50, but then you must add local NYC tax when you buy, and VAT and Duty on import.
Best UK prices today are Sigma 17-70mm £199, 40D £599 (£499 with cashback!), 24mm 2.8 £219.
So unless you fly over, buy out of state and arrange shipping to wherever you are to avoid the local tax and then walk through Customs without declaring VAT/Duty then where is the saving? And don't forget you still ain't paid for your plane ticket :shrug: Even if you buy direct and have it shipped to the UK, after going through all the ID checkin' and credit card copy faxing first, you must add on substantial P&P, you're unlikely to avoid import charges (some will) AND you will be charged a collection fee by the courier. Oh, and are you gonna pay to have the boxes shipped over too? Your choice.
So, I'm really wondering how I am living in dream land here ;-)