the FX5200 will run you around $50 - $75 US. If you save another $100 you can get an ATI 9600XT which is about the best for around $150 (and what I'm currently recommending when my friends ask about upgrades). If you can make the $200 price range the FX5900 nonultra is the sweet spot there, until the 9800Pro drops a bit more.
I have an FX5200 and it's alright (not good) for games from 2002 and early 2003. Most new stuff makes it cry. Halo is unplayable, also Farcry
I am not a big gamer but there are the few new titles that when they do come out I do have a tendancy to try. Right now it's Far Cry, that game is the shyt, but can't run it in all its glory. I picked those cards as I am not sure if spending almost $200+ CAN is worth it right now with new cards approaching and prices then dropping of course.
If you have to make a choice...well, shoot. I guess the 9200 is better, but not by much.
I have one as my secondary video card, and the 5200 in my wife's computer. I'm probably going to dump the 5200 for a Radeon 9600 or better, though.
The performance of both cards is fairly similar, with the 9200 almost always coming out on top by a slim margin, and I have had a lot of compatibility problems with the 5200 for some reason, even though it's basically just a rebranded GF4 MX.