Take a look into a ~$165 128MB Radeon 9600 Pro as well. A ~$100 64MB 4200 is probably a better price/performer for the average gamer, but a 9600P will be faster (much more so with AA &/ AF), will probably have better signal quality (sharper, thus more legible, text) at desktop resolutions higher than 1024x768, and will probably have better-looking DVD playback. The last two features are common across all ATi Radeons, but the main reason a 9600P is more expensive than a 4200 is because it's faster (without and especially with AA+AF) and more future-proof (DirectX 9 vs. 8).
A 9600P is also faster than a 4800SE, so unless you need the VIVO feature pretty much unique to nVidia cards at the moment, you're better off with a 9600P at that price point, IMO.
I think a ~$165 128MB 9600P is a wiser purchase than a ~$120 128MB 4200 at this point. Still, you may not value the extra speed and potentially better signal quality a 9600P will afford you over a comparable 4200, so a 30=50% cheaper and less-equipped (likely only VGA output, no DVI or TV or dualhead) 64MB 4200 may be a smarter move.
Edit: Though, really, depending on what games you play (Sims/Tropico or Unreal Tournament?), you may be satisfied with a Radeon 9100 or 9000 Pro. Neither will be faster than a 4200 at plain rendering, but a 9100/9000P will pull roughly even with a 4200 once you enable AF. The 9100/9000P will also have better-looking DVD playback a probably have better signal quality. You should be able to pick one up for $60-80. 9000P's are all 275/275MHz core/memory, but not all 9100's are 250/250MHz (only Visiontek has all their 9100's clocked at full speed, while Sapphier and Powercolor and other manufacturers have varying speeds for various versions), so it may be easier to just look for a 9000P then have to confirm that the 9100 you want is full-speed.