Don't laugh at me guys I'm poor...this is my rig:
BH6 Rev. C1 w celeron 850 coppermine on no name adapter card @953 (112x8.5)
256 spectec pc133, 128 infineon pc100, 128 no name pc142=512 MB
128 MB radeon 9250
 
I have three questions:
What is the theoretical max FPS on a 2X AGP port such as mine? (I currently average about 30 on Enemy Territory w FRAPS)
Would I be an idiot to buy a Sapphire X1600 512MB AGP for 170 CDN if I am happy just playing Enemy Territory on my current rig?
Am I an overall idiot for even considering upgrading this system or should I just go right to a 939 board w AMD cpu?
I love your forum. I especially like the cpu flamewars, except for when they degrade into the nonsense that you guys call "fanboyism". Big up from eastern Canada.

I think between your celly with a 112FSB, only  128cache, and AGP X2, an x1600 will be badly bottlenecked. Obviously the best route would be a system upgrade to s939,AM2, or Conroe...Even a P4D system would be a HUGE upgrade.512MB is a waste on an x1600 AGP, unless you want to run high resolutions...in which case, the CPU , Memory-subsystem will drag you down. A R9600 or FX5700 will probably be ALL the video card that your system could deal with. GL  
 
 
 
PS. Maybe you can find a used TI 4200-4800 on eBAY, or a R8500. That should blend well with your setup, without being overkill. Sorry for the bad news.  :?