Canada Post Customs cost
By - krispyjung
The Customs charge is determined by CBSA not Canada Post. Because you didn't use a Customs broker to import goods into the country, Canada Post acts as your broker. This transaction costs $9.95 and goes to Canada Post. The rest of the amount that you paid is the GST that you would have paid if purchased in Canada. Some items are subject to further taxes such as tobacco. I am not familiar with importing art but I doubt there are additional taxes. The form that is attached to you parcel contains a breakdown of the fees you paid. It also includes a phone number that you can call if you feel you were unfairly taxed.
It is at least partially based on what the shipper declared.