mailing/shipping to canada

I buy parts from the US all the time. Rock Auto is my go-to for new parts as the pricing including shipping is considerably less than buying local. I would love to support local business but I find the pricing is almost double the prices on RA.
A Cardone distributor is $300 at Napa but is $162 delivered on RA.
I also find e-bay sellers often offer free shipping in the US so I also use a drop ship service to Sweetgrass MT. It's an 8 hour round trip so I either purchase multiple items or find a local making a border run and have them pick up (or vice versa).
I also have sold parts to buyers in the US and quoted shipping from the same drop shippers at a considerable saving to them.
Shipped four wheels-over $200 from Canada to CT but was $92 from MT. That was a deal saver.
Plus I can purchase beer cheap at the duty free and buy soda that we can't get here in the Great White North. One trip I picked up 16 12-packs of Cherry Coke, Vanilla Coke and Diet Cherry 7-Up for friends. Border officer just laughed at that and waved me through!