In my general experience, if you're shipping by air they will charge you by weight + volume because a plane has limited cargo space and they need to work within the max load of the plane where takeoff weight is concerned.
Shipping by sea should mean weight is less of an issue, but certainly volume plays a huge part because it will go into a container with other things.
My guess is you will spend quite a hefty sum of money (>US$200) just for shipping alone from the USA, and that's not even factoring import charges.