I am also searching for a reputable online pharmacy. For some reason, no one ships to Canada, and it is extremely frustrating. I think we have very strict drug laws here or something. I have only found a few online pharmacies that will ship here, and they are insanely expensive. The cheaper one was charging $115 for 30 propecia tablets.. Hair is not worth that much to me.
The cheapest local pharmacy I can find is Costco, which sells generic 30 x 1MG generic Finasteride tabs for $42. Walmart is the second cheapest, at $50 for 30 tabs. For me, considering I spend about $300 on booze every month, this isn't too bad! Just phone your local pharmacies and they will give you prices over the phone.
Costco also sells generic Proscar (5MG finasteride) 30x tabs for $25, but I am having a tough time getting a prescription for it. If you can have a doctor prescribe this to you, it is definitely the way to go.
Good luck, let me know if you find any good pharmacies that ship to Canada!