I don't know about games, but when U use Softimage in shaded view with 3-4 lights GeForce Card will be 6-7 times faster - I hope this helps.
Other suggestion: every GeForce-series card ;
the other "under 200 USD" solution is VX1 - I am using it. It's very stable and fast in wireframes, but in shaded views GeForce cards are much faster.
(excuse my english)