total: $638.50 CAD, AR, assumign you play 1680*1050
if you need, or want to do ityourself, look for combos. it could lower your total to 600 maybe.
sorry i dont the time right now
if you play 1920*1080 and want faster system overall, since that build is quite underbudget,
you can go for i5 750 for 80 bucks more, and a better graphics card for 60~70 more.
if you had to pick one upgrade, video card to 5770, keep processor at i3. thats all you need for gaming really. video card is more important at higher resolutions anyways. just make sure you slightly oc the i3 for way better performance for the price. http://www.tomshardware.com/reviews/geforce-gtx-460-radeon-hd-5570-gaming,2697-3.html
keep in mind of neweggs ridiculous shipping prices >< and also ridiculous 13% tax
edit: sorry forgot to include optical and os. so add anotehr 120. right in budget pretty much. i guess you dont need to upgrade after all