Best affordable video card to get: Quadro based vs nVidia

Okay so my PC’s specs are:

AMD Athlon 2000+ @ 1.6G
1G of RAM
Premiere 6.0

Since my computer is more than a few years old I don’t want to invest more than $200 on a new video card. I am leaning on the PNY Quadro4 280NVS AGP 8X 64MB DDR. That’s the only Quadro based card I could afford for now. Will it be enough for video capture and NLE? There are Radeon and Nvidia cards with 128 or more DDR that are cheaper. Which way should I go?

I appreciate everything I have learned from this site and forum so far.

Thanks - Rodger