Just stick to the Canadian Steam. Generally most games aren't even upmarked by that much. Like, if a game is 9.99 on the US Steam, it'll be 10.99 or something on Canadian Steam
For new games you generally have a lot better purchasing options anyway. Like I mentioned before, GMG and Nuuvem essentially become your best bets for new games. Maybe even Gamesplanet to some extent.
In the past few years, Steam has had its thunder stolen by a lot of other online retailers. I'm not even remotely interested in the Steam summer sale this year, because PC game sales are just seemingly ubiquitous and never-ending now a days.