Any ideas for lower shipping/import costs on framesets from overseas?

I'm looking to get my hands on a bike built by a UK framebuilder (Genesis).
I have been quoted 120£ to ship a frameset to the United States.
I also once purchased a framebundle from On One once and the post office surprised me with a significant fee, some kind of import costs they couldn't quite explain. (I didn't know at the time about planet x USA, or I would have saved myself this pain).
Does anybody have any ideas on how to avoid surprise duties or fees, and possibly to avoid or lower costs on shipping a frame from across the pond?
How do you UK folks get your hands on frames from smaller US builders?
Please let me know if anybody has ideas.

Thanks