THE 9200 DOES NOT SUPPORT DX9 FEATURES. At least, not any more than any other DX8 card, like the 9100/9000/8500/GF4/GF3. It's DX9 compatible, not compliant.
I've seen this in a couple of threads, and it's not true. The 9200 (RV280) is simply a 9000 (RV250) with AGP 8x support. I also haven't seen it in Pro form, and neither the 9000P nor the 9200P (if it exists) can really compete with the 4200 in terms of speed, though the gap between the two would close with AF on. An 8500/9100 is a better 4200 competitor, but still slower (yet cheaper, so it evens out).
Your choices for 128MB cards are:
$200 9700 (Sapphire @ Mwave/ Powercolor @ GameVE)
$170 9600P (ATi @ Mwave/Sapphire @ Allstarshop)
$150-160 FX 5600 (bunch of places)
$140 4800SE (bunch of places)
$140-150 9500 (Sapphire @ Allstarshop & NewEgg--potential mod to 9700)
$100 4200 (Albatron @ GameVE)
The 4200 and 9700 are probably the best price/performance cards in their price leagues (the 9700 can be 2x as fast as a 4200 w/AA&AF). The 9600P may be better if you have a weak PSU. The 5600 isn't really an exceptional buy ATM, IMO; the 9600P outperforms it with AA/AF, and the 4800SE outperforms it without. Still, if you value DX9 and must buy nVidia, consider it for future-proofing. The 4800SE is a good card if you don't value AF or AA. The 9500 is a dark horse; it shines once you enable AA & AF, and you may be able to softmod it into a 9700, but otherwise performance is relatively unexceptional. The 4200 is just a solid card, but it won't be as pretty as the others, as it's really not fast enough to enable AA & AF, except maybe at low levels.
As always, the Radeon cards offer better 2D and DVD playback than the GF4 series, but the FX series should be better in that regard.