It as nothing to do with the country you purchased the bag from, it is where the bag was manufactured.
So, if you bought a handbag for $450 from Canada, BUT it was manufactured in France or Italy, then customs would apply.
Yes, the U.S. has a $200 exemption. Any purchase valued over that, would be eligible for fees/duty/taxes.
The seller has absolutely no control over the buyer's home country's government customs. It is the responsibility of the buyer to research this info and understand exactly what they may be facing by importing an item into their country.