I agree with Steel_Fish 100%

I have the GeForce3 T4, and it spanks. Was $350 when I bought it a couple years ago, but now they are running about $100-$150. An older card yes, but few items on the market can take advantage of its power. Everything I have run on it I can kick the graphics to their peak and it still flys along. It helps having the DDR, which is essentially a dual architecture allowing all graphics to be handled by the board processor and not your main board processor.

As long as your processor is high enough, it is a great way to go.
I am running an Athlon 2.4 with 512mb of RAM so it is a blur for most applications.

Good luck Carl, you have opened a can of worms once you get into this stuff!!