I'm also in Canada.
If you want to save big bucks, it will cost you in time and effort. So weigh out which is worth more to you. What I did for my $2000 PC a number of years ago was getting the big 3 here in Ontario (TigerDirect, NCIX, and CanadaComputers) to compete against each other.
As they stand as far as retail prices go, in order of least to most expensive, they are ranked CanadaComputers (CC) = NCIX, TigerDirect. However, they all have markup that they are willing to negotiate.
Here was my SOP:
1) You start off at CC/NCIX and you get them to give you a paper copy of your system build with their accompanying prices for each component. You tell them that you'll think about it, and take said printout to the next store.
2) You tell them that the previous store is offering you these prices for these components, can you beat it? They will huff and puff but will eventually beat it. Tell them to print out a NEW paper build, and will come back after some more deliberation. Take the new sheet to the next store and repeat.
3) After the first round of negotiations, go back to the first store you went to, and this is where it will be up to your judgement of how much more time to invest in the process. They will either beat it, or not, because you will have chipped off so much of their markup that you're approaching "at cost" prices. You stop the process when you feel they really can't do any better.
Note - keep in mind that some individual components may cost more at one store than another, but as long as the WHOLE build cost less at that one store, it is fine. Get the whole build done at that one store.
I priced my i7 920 Crossfire build off newegg at ~$2000 at the time but finally paid ~$1600 for the whole thing at TigerDirect. It was quite comical because one manager signed off on the build at ridiculously low prices, but when I returned to agree to it, it was another manager on site, and he was furious, saying "WTF, who signed off on this? We're not making any freakin money." But they had to honour it. Cashing out took a while because the system wouldn't let the cashier check out at the prices I got, almost everything needed a special manager's override code.
In the end, it takes tough skin (leave your dignity at home lol) and patience - it took me a week, but I saved $400 off retail prices. Weigh out if it's worth it for you. Maybe do 2 stores to save time?