I went through to the checkout on that site final price was £394.19 the shipping was £9.99 and the vat was £ 65
I think in the US the price is around $450 then there would be shipping then the vat on the cost of item plus the shipping and the fee from the courier that is collecting the vat etc etc the UK company price is ok and less trouble
The customs forms have to have the value of the item and vat at 20% is then added to the item value and the shipping cost the shipping company will send you a snail mail with the cost of the vat plus their administration fee for collecting the vat and passing to the treasury this has to be payed prior to the goods being delivered
Brian