Just a couple of things to consider.

Shipping cost per kilo & the Canadian to US dollar exchange rate.

Just a hypothetical example:

The magnets pay 1.00 Canadian dollar per kilo.

That would currently convert to .76 USD / kilo

Multiply that .76 USD x .453 and that works out to a payout of about .34 USD per pound.

As you can see ... it might be a problem to make the numbers work once you factor in shipping costs.