Looking for a new video card

[Sephirdorf]

I currently have a ATI Radeon X1200 which uses pixel and vertex shader 2.0, however alot of games now require 3.0 or higher. On several "can you run it" sites i'm always informed that my video card is the only thing stopping me from playing the more graphically stronger games such as mass effect and starcraft 2.
Can anyone recommend any affordable 3.0/higher cards, i've never purchased a video card before so I am currently unsure on which one would be right for my computer.
My operating system is Windows Vista 32 bit