Technically, anything over $20 CDN is subject to custom duties and taxes.
http://www.cbsa-asfc.gc.ca/import/postal-postale/duty-droits-eng.htmlThe item’s value in Canadian dollars
Under the provisions of the Postal Imports Remission Order, if someone mails you an item worth CAN$20 or less, you don’t have to pay duty or taxes on the item. If the item is worth more than CAN$20, you must pay the applicable duty, the GST or HST, and any PST on the item’s full value.
Handling costs
To process goods imported as mail that are subject to duty and/or tax, Canada Post charges the recipient CAN$9.95. If the item is duty-free and tax exempt, no amount is charged.