If you buy items from the USA, here is "THE" FACTUAL places where you can get information, and does not apply only to FLIRC, but to all goods, note that it is NOT Canada Post that applies the fees, but CBSA:
One item you will need to know is that if the product is considered manufactured in the US or Mexico and is duty exempt under NAFTA, though you may still have to pay taxes.
You can also ship to a "pick-up" location along the Canada/US border for less money, and works best if you make other pickups regularly.
Also note that "You may have to pay duty, the goods and services tax (GST) or the harmonized sales tax (HST) and the provincial sales tax (PST) on items mailed to you. If you owe duty and tax, it will be indicated on Form E14, CBSA Postal Import Form, which will be attached to your mail item when it is delivered." It doesn't always happen at lower dollar amounts. You do NOT have to pay the postman, but can pick-up the package at your local Postal Outlet.
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http://www.cbsa-asfc.gc.ca/import/postal-postale/menu-eng.html
Postal Program -- Importing by Mail
How the process works
As with all goods coming into Canada, a proper declaration must be made on any items being imported by mail to enable border services officers (BSOs) to correctly assess the incoming goods.
When an item is mailed to Canada from abroad, the sender completes a customs declaration form giving the value, origin and a detailed description of the goods.
Upon arrival in Canada, all international mail items are presented by Canada Post to the Canada Border Services Agency (CBSA) to process through the Agency's Postal Program.
BSOs visually inspect each piece of mail to determine its admissibility and confirm whether it contains dutiable or taxable goods. If the BSO determines that a mail item is not prohibited from entering Canada and is not subject to duties or taxes, the item is released to Canada Post for immediate delivery.
Otherwise, the BSO forwards the item for further inspection by the CBSA or by another government department or agency before the item can continue in the postal process.