[jariel]

While I don't doubt that building more homes brings prices down, the real reason housing is cheap in Montreal is because Montreal is poor, has lower immigration, little in the way of industry to attract migrants, language barriers, and it doesn't have a basis of Chinese ex-pats to anchor a lot of foreign buying which is a huge driver of prices in Toronto and Vancouver.

Edit: I should add, I live here and am very intimate with the issue.