I prevously(before it burned up on me) had a 9800 pro video card, 128 MB, and I was able to run COD2. It was choppy in some parts of the campaign, when theres 50 guys on the screen, but it was definatley playable. You might be able to find one for less than $100
I found one for $104-->Newegg.com is your friend
http://www.newegg.com/Product/Product.asp?...N82E16814140058
I found one for $80 (on sale)
http://www.directron.com/r98esc3.html
I dont think I would go with anycard less than the 9800 pro having played COD2 with it.
I hope this helps you.
BK