If you're in the GTA and are using one of those TigerDirect outlets check out Canada Computers first:
Canada Computers - Your Neighbourhood Computer Store and Service Centre - PC Systems and Hardware Components, Notebooks, Electronics, and more.
Their prices are generally lower than anywhere else (always exceptions) and have a number of stores in the GTA for pick up rather than delivery. That's what I've done and its saved me atleast $150.00 on my build over TigerDirect.
[edit] And they price match as TigerDirect wont unless your ordering your entire system from them at once...and then it's just a discount if you make a good argument. [/edit]