Don’t know if this would be useful to anyone, but I have used shipito.com to provide a US address, and forward parcels.
For a fee they will also buy items with their credit card, but I just used a UK credit card.
I got a snowboard that cost £250 in the UK for $120. It ended up at about £160 by the time shipping and customs were paid. The biggest bummer was TNT charging a flat £15 fee on top of the vat/import.
The crazy thing is that the board was made in Europe, by a European brand!
The shipping actually cost less through shipito than the online shop (who provided free delivey in the US).