Couple people said that even my PSU is 250 watts since it has 16A on +12V they said it will work but it that true? I have a PSU that came with my Dell 170L tower. Or does how many Amps doesn't matter and what matters most is how many watts it has? I remember having a PSU that was 150 watts and it had only 4A on an old tower and people said no video card would work but when I used a ATI Radeon 7200 32mb it worked fine. One forums said the amps is what's most important but I basicly I need to know what is most important for a video card the amps or watts.
No, that Power Supply is not sufficient, even if your graphics card did work your at great risk of damaging it and the rest of your system with such a basic power supply.
I wouldnt go any lower than this Silverstone 400w PSU for 48.99 or 38.99 after rebate, I have the next model up(500w) and it works excellent with a AMD Phenom X4 955 and 9800GT LPE(Overclocked to standard speeds)
but, for a better price/value buy I'd get this OCZ Fatal1ty modular 550w psu it costs 64.99 or 44.99 after rebate and it is modular, this will allow better cable management.
Cheapest you will get(while still being of a reliable quality) is this silverstone 400w psu its 48.99 or 38.99 after rebate, its not what I'd recommend but if you have to this is the cheapest I would go, Keeping in mind it's only 400w so your future upgrade options are limited.