Costco.ca generally carries a very limited selection of Lego on permanent discount. The best deals right now are:
8110 - Unimog - $189.99
42000 - Grand Prix Racer - $119.99
Free shipping as well.
Deal expires whenever costco decides to stop carrying the sets.
I don't think you need a membership to order online, but haven't yet tried without one.
http://www.costco.ca/building-blocks-se ... 27%2b12422