No, that would do the opposite. Import tariffs are paid by the buyer and export tariffs are paid by the seller. It would still raise the price for the end customer, but at Canadians’ expense instead of at Americans’ expense.

Think beyond step one.

I'm highly confident the Canadian sellers would feel no need to do the US buyer any favors, by shouldering the export tariffs. In response to the creation of export tariffs, Canadian sellers would raise their prices the account for the new costs, those costs would be passed onto US buyers. Because the net price of the item the US buyer is paying doesn't change, the US buyers wouldn't even bat an eye and simply pay it like they always do.

While a business owner might have a mild interest in the geopolticial reason for an expense, to the business, the reason is immaterial. The result is what matters; how much the invoice is to get X input the business requires. If they have previously been paying $5 extra per unit to the US Government for import tariffs, and that disppears but the price of the item from Canada goes up $5 (because the Canadian seller raised the price to cover the new export tariffs the seller is paying), the end resulting price to being the exact same and it is simply business as usual to the US buyer. In this case here, if the US buyer's price doesn't even change, I'm not even sure they'd notice.