Derby Runner is excellent I have to say!
In relation to the arguments above, a lot of research in different markets indicates that UK prices are indeed much higher than in US and some other markets. Say 10-20 per cent depending on the market.
Manufacturers claim that the market here will STAND higher prices (i.e. people will pay more) and that the supply chain is longer and with higher overheads (which is mostly untrue in say the automotive sector and software licensing, which are well investigated).
Best way to get reasonable prices is to be member of a good affiliated running club and take the discount at LOCAL shops, normally 10 percent. They are normally staffed by runners and people who know the kit, unlike telesales staff in some of the distance selling companies. Not everyone has that luxury though.
Some distance retailers are not passing on their lower overheads to customers, and some are. Shop around, and a pattern quickly shows up. You also have to pay postage, be in to receive the goods and deal with occasionally obstructive companies who assume you won't apply the Distance Selling Regulations 2000 when they fail to deliver. Don't forget it is the vendor who is responsible for delivery and ensuring you get your goods.
Buying direct from the US is difficult, and unlikely to be cheaper with postage and the possibility of customs duties.
If you run or know anyone running a race in the US, stock up! The market here is unlikely to change significantly.