For $75 you should be able to find a Geforce4 Ti4200 or maybe a Radeon 9600 non-pro.
Yeah, you'd see a big difference, but probably only in Medal of Honor... Simcity, Civilization, & Golf games won't be as much of a bump. (Maybe newer golf games).
P.S. Never buy a Radeon 9600SE.
<b>Radeon <font color=red>9500 PRO</b></font color=red> <i>(hardmodded 9500, o/c 322/322)</i>
<b>AthlonXP <font color=red>~2600+</b></font color=red> <i>(o/c 2400+ w/143Mhz fsb)</i>
<b>3dMark03: <font color=red>4,055</b></font color=red>