Also simply that the UK is a smaller market with less competition, and UK consumers are largely used to being charged at these levels (I lived in the UK in the early '90s, and the "$ = £ for imported tech goods" equation was exactly the same then). Importers are going to charge as much as they can until people stop buying, and apparently, people aren't.
I think this is particularly the case for specialized niche equipment, as it tends to be bought only by those who really need/want it, so demand tends to be relatively price-inelastic...
