as far as importers, theres companies that already buy from some of these suppliers here in the US, the monkey, grom and supercub stuff in particular. there isn't enough demand here to stock this stuff for the trail though.
as far as shipping, i buy a LOT of stuff from overseas, one shop in particular in the UK for vintage yamahas, including vehicles they never sold in the states, and none that have been made in the past 30 years FedEx is 21 bucks shipping every single time, and i get it in less than 5 days every time, and these are NEW made parts, not new old stock. Its a (lack of market) demand thing, plain and simple. shit, im still waiting for the clutch part from Malaysia, its been sitting in outbound for 3 weeks.