In general the prices you see for any hobby related products, not just cameras is about the same in British Pounds as they would sell for in America in US Dollars. Although prices displayed in the UK have to include our 20% sales tax (VAT). My other hobby is Shooting where the vast majority of products are still manufactured in the USA so that may account for some of the difference as we have to allow for import duty as well as the VAT. I'm not so sure about cameras though as in general they are imported in to both of our countries.
The most annoying thing though is to see products the were exported tfom the UK to the USA also selli.g at parity prices.