Having lived in the UK most of my life before moving to the US, it's a fact of life that most stuff costs more there. This is partially due to VAT (Sales Tax) of 17.5%, partially due to the smaller market size, partially due to higher overheads paid by businesses (tax gouging by the government), and also because of retail price gouging over decades.
There used to be a huge difference in car prices between the UK and other Euro countries a while ago. There were a number of businesses set up purely to help people order their cars from other Euro countries, and transport them over to collect their cars and drive back via ferry and sort out the import taxes with customs, and still save a ton of money. The car companies hated it and tried to negate warranties, but they failed.
Prices are actually a lot more equivalent now than they used to be, but there's still a mark up. It's a case of charging what the market will bear, and currently the market is bearing it.