For under 100 what can I upgrade a Nvidia GEforce 7300 GS to to fix my terrible framerate in World of Warcraft to much higher numbers and if not possible under 100 please list cheapest options

The ATI Radeon HD 4650 runs for about $70. It is in my opinion the best budget card out there. Its a HUGE upgrade from your 7300. Go check out tigerdirect.com