Best...site...ever... There aren't a lot of comparison-shopping type sites in Canada (AFAIK), but I stumbled upon this one, it's really helped me with my build. The cost adds up significantly cheaper by referencing this site rather than by judging the approximate prices by a few of the known cheaper retailers....which means I can buy better components on my budget. I'm sure all the canucks on here know about it, but just thought I'd pass it on in case anyone didn't (edit: you'll get more results for a lot of things if you enter the product number rather than name if you are looking for a specific item).
Most places the 6800GT is $50-100 more than the x800xl, but one place is offering the MSI 6800GT for $25 more than the cheapest x800xl I could find (the ATI, I think), so hells yah. Still have to check out some retailers at College/Spadina in Toronto, but I don't think I'm going to beat this price.