A full size bike box is going to cost a fortune from anywhere. It will be cheaper to send the wheels in a seperate box, if they're special. If they're not, get the seller to donate them to a cycling project/the kid down the street/whatever, and just send the frame and components.
The value of the sent items will be lower, postage costs will be lower and duty will be levied at a lower rate than for complete bikes.
It does cost a small fortune to send stuff from Canada. I was quoted $350 for an immaculate Brodie (it still hurts!) sent by steam packet. Airmail was $600 ish!
From the US it will be $75 ish per frame size box, so if it can be smuggled across the border and sent from there there are big savings to be made.
Give a man a gun, and he can rob a bank.
Give a man a bank, and he can rob everybody.