I'd take a look at the newer Radeon cards. This summer I bought a GeFX 5200 Ultra for around your price and it didn't really deliver. You won't be able to get top of the line but you should be able to get something decent. According to PriceWatch.com you could get a Radeon 9700 128MB for $159 and a Radeon 9800 128MB for $138 (this one sounds kinda goofy). I'd check out the 9700 route though.
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