Hi ismailsh.. I believe there isn't any duty but if pulled for inspection will be charged normal taxes for your province GST/PST/HST. + by mail , an $8.50 fee. Couriers, UPS/FEDEX charge an expensive brokerage. Avoid.
Many items by mail slip through without but don't count on it.
Another complication i see is eBay's new global shipping program. US sellers are getting on board and Customs charges are paid on checkout. A listing will show a reference to import charges at checkout. My comment about slipping through is moot.