If you flying from US yes you have to pay but I don't believe the canadian people have to pay for the entry permit. Also it depends of the airline are you flying with because some require you to pay for the insurance and they charge you the same amount and give you the permit but really I never heard that for non american-cuban travelers.
By the way here is some information that you can use.
All travelers to Cuba must possess a valid passport, a return ticket, travel insurance policy with medical coverage, and a visa or tourist visa. Unlicensed U.S. citizens may be allowed a stay of up to 90 days upon entry. British citizens are granted 30 days upon entry. This can be extended for another 30 days within Cuba. Canadian citizens are granted a visa for 90 days. This can be extended for 90 days only.
For Residents of Canada -- Contact the central Passport Office, Department of Foreign Affairs and International Trade, Ottawa, ON K1A 0G3 (tel. 800/567-6868; www.ppt.gc.ca).