You're comparing apples to oranges. How much does your VAT add to the cost? How much is a liter of gasoline/diesel taxed in your country (my understanding is it's about 80% in the UK)? What's the NHS overhead per employee? At what age can a worker retire at near full salary?
All these costs add up and every one will be passed on to you as a consumer. Every corporate "tax" is paid by the consumer in higher prices for goods. Yeah, some of the premium you pay *might* be greed but it's greed on your side of the pond. My bet is that most of the premium is charged because your dealers have to do so to stay in business.
No, that is not strictly true. If you understand how the UK economy works you'll realise when you strip out the know reasons for increases (VAT, import, FX etc) you still can't get to a value that is even comparable.