Dude I'd love to help but everytime I buy from the states they KILL me on import tax. Over £20 at times. My dad used to work for the post office and he doesn't know a way of getting round it either.
The only idea I had to get around this in future would be to find someone else who want's something sent over as well and place it as one order, then split the customs charge.
Other than that I don't know of anyway around it. Let me know if you figure anything out.