First off, no, susieboxer, I don't have things wrong. It's a terrific expense to buy items in the UK and have them shipped to the US. Often the shipping on things I buy that way is greater than what I paid for the items themselves. It's a two-way street, obviously.
Tiggerstitch, thanks for the explication of the "minefield" of varying rates for shipping. I knew that FedEx was awfully high in their international rates but I didn't know about the customs and VAT charges. You say these can be avoided for the most part by using the US Postal Service and not insuring anything for more than £30? Do I have that right?