I'm just learning this stuff now. But this is what I'm learning for the duty rates (tariff):
Canada has many tariff classifications based on country of origin. The general tariff is 35%. Tariffs for products originating from NAFTA countries are mostly 0%. The tariff rates for goods are listed here:
http://www.cbsa-asfc.gc.ca/general/p.../01-99r3-e.pdf
List of countries and their tariff classifications:
http://www.cbsa-asfc.gc.ca/general/p.../2005loc-e.pdf
This link describes the tariff classifications (Most Favored Nation, General Preferential Nation, UST, CCCT, LDCT, MT, etc):
http://www.cbsa-asfc.gc.ca/general/p.../2005act-e.pdf
For example, to find out the tariff for a snowboard that you mail ordered, check this link (page 7):
http://www.cbsa-asfc.gc.ca/general/p...005/ch95ne.pdf
This shows that if you bought a snowboard that was made in Japan, then the tariff will be 7.5% because Japan falls in the Most Favored Nation category but doesn't fall into any of the Beneficial Nation categories. However, if the snowboard was made in Brazil, then the tariff will be 5% because it falls under the General Preferential Nation category. Now, if the country of origin of the snowboard falls in one of the other beneficial categories (UST, CCCT, LDCT, MT, MUST, CIAT, CT, CRT) then the tariff will be 0%. Finally, if the country of origin does not fall into any category, then the tariff will be 35%.
This link shows provisions to the tariffs rules (for non commercial purposes only). It shows that if you leave the country, you can bring stuff back without paying tariffs or have a reduced tariff (within limit):
http://www.cbsa-asfc.gc.ca/general/p...005/ch98ne.pdf
Using the snowboard example, what this tells me is that if you brought the snowboard back (not mail ordered) into Canada after 48 hours outside the country and the total value of the goods you are bringing back is $200 or less, then the tariff is free. If the total value is between $200 and $300, then the tariff is 7% for snowboard made in Japan and free for the snowboard made in Brazil.
If you have been outside Canada 7 days or more, and your total value is $750 or less, then the tariff is also free.
If you have been outside Canada 24 hours or more and your total value is $50 or less, then the tariff is free.
You can see it gets pretty complicated. If I understood these publications right, then this should help answer your question about the duty. You'd just have to look up the tariff for lamps if it exists.
You then have to pay GST and PST on top of the tariffs of course.