look in regions --> Montreal, there is a lot of information about tremblant in those threads there.
What date are you gonna be there? I go up there for the day a lot.
Honestly, unless you are with a group, there is no cheap way for you to get a ticket. I've heard of tickets being sold at Costco quite cheap, so keep an eye out for those.
You should also know that Tremblant is the most expensive place on planet earth (besides maybe Vail/Whislter), so heads up..
oh and if you into the whole park thing, they have 2 parks that are free and the main park requires a park pass ($$). You can often sneak in if you look the part though.... just bring your tall T and glock 9