Interesting...
I've just booked YVR-YYZ in C on cash & miles.
BMI is charging £150 in "taxes" whereas aircanada.com prices it out at just £60.
bmindia are adamant that the taxes are all going to AC, but are also refusing to give me a full breakdown of where the tax is going. The tried to tell me that £144 of the charges were related to the airport improvement fee at YVR