Having looked at points 1-6 made by Simon Galley which I am not denying are part of any products costs, I cannot reconcile this with the correct statement made by pdeeh that it is possible to buy from the U.S. cheaper than from the U.K. certainly for some products even after taking all charges into account.
Simon gives an interesting analogy with car prices between the U.S. and Europe and it was this mention of car prices that sparked my memory about the massive car price differences in the late 80s between some European markets and the U.K.
When questioned about this car manufacturers cited a list of cost similar to Simon's and it appeared that the differences were fully justified until someone decided to try importing cars from the cheaper markets and did so successfully and more cheaply. Re-importing then became a minor industry in itself and any customer could order a car this way and even after paying the middleman's fees still bought more cheaply.
At that point car manufacturers who had said they couldn't reduce prices then did so - at least to the point where it wasn't worth the trouble and hassle to import.
I fear we are charged what the market will bear and unless and until I see a convincing argument to the contrary, this will continue to be my belief