M. F, I know of a homebrewing place where you can find CO2
Le Choppe à Baroque, on St-Dominique and Villeneuve, I think.
I baught mine originally from there... But guard X on papineau sells and refills co2 tanks!
Liquid Canada or whatever it's called sells 5 pounders but at an expensive rate... A refill is 45$ where as at guard x it's 21$... Brand new tank I don't really know how much it costs... But like usual Canada, Quebec actually is expensive -_-
Oh and praxxair there's a long wait on refills :/