ok..im assuming your in canada because you want it in canadian dollars
honestly, ebay is your best bet. I got my 90g with everything except the fish for $400..you just have to keep checking for deals
failing that (which is highly unlikely) try bigalsonline.ca or go to Big Al's fishstores...they're so good, informative and friendly..and their prices are reasonable.
Shopping for price, your best bet is going to a big-als store and picking it up. Not much online shopping in Canada, even big als doesn't sell the tanks online in Can, except for some lousy kits. If it's just a small tank you want, nobody can beat walmart.
There isn't much online store in Canada that sells aquarium of any size. Frankly, you would be better off to just get one from Wal-Mart. Once you have the tank, there are a number of Canadian online store for supplies and equipment. One that I will definiately recommend is www.jlaquatics.com. Also, check here too: http/www.fishforums.net/index.php?showtopic=77715&hl=