Paul I ship clipper cargo all the time! Dirt cheap to ship inside the usa all you do is have them ship to the clipper in downtown seattle and it gets brought over on the next sailing. Id say a package of that weight would cost you about $30 to get brough over and then you take the paperwork up to customs, you are your own broker so zero fees there, juwt pay tax on it and bam you're done!
Probably used them a dozen times over the years...tires, seats, full quarter panels etc (even better deal if a private sale and you get a reciept for the super low price you paid....less tax wink wink nudge nudge)
Call me if you need more deets