There's really no rhyme or reason.My reply above does not convey how much I sympathize with your situation. That total cost would be extremely hard to take. Is it based on the total value of the contents? the weight? the category it falls into? Because I’m wondering if there are ways of ordering in the future that could help to mitigate the costs.
YES, there are schedules or what have you detailing how much the duty is per gram, et cetera, only... these are HARDLY EVER followed. In the praxis, it seems to depend on the mood or idiosincrasy of the agent doing the processing and/or the instructions from supervisors at that facility at that particular time.
A lot of Canadian law is inherently ambiguous. Some say such laws musta been written by idiots, seeing how ambiguous, and even contradictory, they are at times. Baloney: it's not idiocy, but malice. The laws are DELIBERATELY ambiguous so that law enforcement can exploit situations and technicalities in each particular case if they so desire.
Thus, the tables and schedules are meaningless for the smoker trying to decide on how many tins to buy from Laudisi and friends. The fees are all across the gamut.