Shoutbox

You won't get much with 800 CAD (about 520€). I don't know how much hardware costs over there, so I'll go with Finnish prices (which are a bit higher I suppose, but it shouldn't differ by that much).

-You wanted a good graphics card, and those are quite expensive. A top of the line card, like the GeForce 8800, is a bit less than 400€ (600-ish CAD), and a bit older one, like the Radeon X1950 (which I think is kinda popular), is around 200€ (around 300 CAD).

-1GB of memory is about 70€ (100 CAD).

-Now, for games you don't only have to have a good graphics card, but also a decent processor. You can get good ones for around 150€ (230 CAD), better ones are naturally more expensive.

-The hard drive isn't cheap either, but if you have a old computer you can salvage it from that one.

-Motherboards range from 50 to 150 euros (80 to 230 CAD).

At this point you are at the 700 CAD mark, but you still need a power source, DVD-drive, case, maybe a HDD, monitor, keyboard, mouse and speakers (those can also be salvaged of a old computer). Then you would have to build it together yourself or let a company do it for a fee. You might also need a operating system.

It seems that it is possible to get a new computer for around 800CAD, but it won't be top-notch. I don't know about the prices over there, so there is a good chance you can get components cheaper than I said. Make and model also make a difference. My advice to you would be waiting some time (or maybe negotiating with your parents for some extra money). There might also be some ready build solutions, but those are usually more expensive than assembling the computer yourself.

Perhaps some other Canadian can give a bit more details?