Canadians can purchase items up to $20.00 Canadian, from U.S. Sellers, with no excise tax due, according to our Trade Agreements, whereas, U.S. buyers are are permitted to purchase $200.00 U.S. , worth of items, from Canadians without paying any excise tax in their country.
Many of the U.S. sellers that I have spoken to, about their Global Shipping are very accommodating and are more than willing to ship through their post office for you, at a much reduced cost. You simply have to ask them.
You have the choice to avoid sellers that use UPS due to the Price Shock at your door, OR seller's that use Global Shipping and charge import taxes on items under $20.00 Canadian, where no import charges are due. These forms of shipping can turn the excitement of your purchase, into a bitter experience.