Reddit reviews ZOTAC nVidia GeForce 9800GT B-Hawk 512 MB DDR3 VGA/DVI/HDMI PCI-Express Video Card ZT-98GES5P-FDL

I would recommend a 9800. Mainly because I've been playing TF2 with a 8800 GS that just burned out, and I was able to get a 9800 for $50.

Ya. That's pretty low. You aren't going to get much of a video card upgrade without upgrading your power supply. Maybe this, it doesn't require any additional power connector either.

I think you'd be better off saving that money for a new PC upgrade in the future. If I recall correctly, 2GB of RAM for DDR2 is ~$35 whereas 4GB of DDR3 can be had for ~$20 after MIR. Depending on the games you play, a video card upgrade may be good enough for now. Check this to see how your graphics card scales up. For your price range, you should be able to find a 9800 for ~$50, and it's a lot better than the 430.

EDIT: Oh, Newegg doesn't sell the older cards any more. Well, you could always check ebay, R/Hardwareswap, R/Computebazzar, or just ask friends/people. For example, Amazon has a 9800 for 64+5 shipping, and that 9800 is far better than the card you listed. However, I don't know what the Canadian difference may be, and you can get one for a lot cheaper used. I also have a spare 9600GT, if you want to buy it :D But just check around, you can find something decent for your price range.