With no offense intended, $50-60 will not purchase a new graphics card capable of playing today's games, and may not purchase a used one either.
Unfortunately, it would have been far better to purchase a less expensive processor such as the Athlon XP 2500+, as systems are a balance; a fast processor will be hamstrung by a poor video card in games. As that's water under the bridge, here is the advice I can give based on ten years of experience.
You could purchase a "get by" card for that price right now, but the best bet would be to try and find a way to afford a little bit more than what you were looking to spend; it will last longer, and you won't end up buying another video card in 6-10 months. I looked really hard on my price search engines to see what I could find, knowing you're probably on a limited budget. Every card even at the $100 level still has at least one compromise that will probably result in you getting a card that is limited in one way. I also didn't look at refurbished products; enthusiasts like us may be willing to gamble, but I wouldn't recommend it to someone who is still new to the scene, and I also stayed away from a lot of the cheaper less scrupulous vendors; I saw some who charged a really low price, and then wished to charge a customer extra for the heatsink/fan on the video card.
The best deal I found was a BFG Asylum GeForce 4200 Ti 128MB for $72.00 + shipping (should come to $81.00 total) from this site:
http://www.logicalplus.com/bfgasti128xa.html
The BFG cards have lifetime warranties, a big plus. This card is two generations old, and I have never ordered from this vendor, but if your budget is firmly fixed, it is the best you will find for under $100. It should run today's games reasonably well.
Should you decide you can stretch your budget a bit further, the best video cards for low dollars really start around the $140 range, where you can find Radeon 9600XT-based cards. As an example, I found this card for $132+shipping from a site I have ordered from before and trust:
http://www.gameve.com/gve/stor...ils.aspx?sku=VC-VT-004
Admittedly this card is double the budget you stated; however it will last longer before upgrading and will enable additional graphical features to be turned on in his games. These are the two best choices I could find; I hope you will find the links useful.