I don't understand it myself. I've shipped to Canada often enough as a private citizen with no trouble, and I''m sure a business that does it regularly should have it down to a science. Looking at the huge volume of trade between Canada and the US, it's obvious someone is doing a lot of shipping back and forth!
Your best bet is to find which the generally accepted best dealers for any knives are, and check out their Leatherman prices.
Anyway, recommendations like this belong in FEEDBACK (GBU) so I'm going to move it there from the Multitool forum.