I got stung a few months ago when I bought two Amal carbys for the BSA's I'm restoring. The carby's cost me a bit over $1000 plus postage. In the end I had to fork out another $300 for the import duty/gst just to get the carbys, which pissed me off no end. Unfortunately I was unaware of the tax at the time.
If you bring them in one at a time you wont get charged or just sell them and charge GST. This is an argument I have with our customers everyday why are we so much more expensive than a USA online store.