Just make sure it's not a 5200 that's gibbled with a crappy 64 bit memory interface. All 5200's are supposed to be 128 bit, but some manufacturers have cut costs on the memory interface and it'll make it run like a Geforce2 MX.
If you can afford it, spend an extra couple bucks and go for a Geforce4 Ti4200 or radeon 9500 non-pro. It's worth it.
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Radeon 9500 w/256 bit memory bus @ 367/310
AMD AthlonXP 2000+
3dMark03: 3439