Reply by Charlie

You are not working in the US if your studio (or shop) is in Canada and that’s where the pieces are created.

However, I think you should be asking this of legal council in Canada to get the straight story. I know I’m not a tax/customs/fee-and-license expert.

If it’s only a couple hundred dollars, ship the stuff to AZ and let them worry about it. That’s assuming you’re selling to the place in AZ and THEY’re actually retailing the items. If it’s consignment, ..... not enough information and any advice offered might just as well be a guess. :)