Decent video card for low price?

A HD 6770 would be a decent gaming card for your budget , something like this is under 100 bucks with rebate and a free game
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

will my system support it? I don't want to find out that i need to buy a new Power supply.

Im not too familiar with your psu but 400 watts should be enough as long as you arent doing overclocking and have too many other perpherals in your system. 450 Watt is recommended but you can get away with it.
You can always go for something lower than a 6770

okay. so 400 watts should be fine? thanks  

DiabloTek isnt considered one of the more dependable PSUs out there. Just so ya know.

ya I know. It came with my case. I know i am going to buy a new PSU someday but not at the moment at least.

NO! Your Diablotek PSU-shaped object will blow chunks on just about anything. It is not fit to power computer equipment. It might...might run a HD6670; problem is, it is such junk it may die anyway for no apparent reason (actually, the freezer in the basement cycled on), and when it does it is likely to take other parts with it. Add another $45 to your budget and pick up an Antec Earthwatts or Corsair Builder; then you can get a HD6770 or whatever will fit in your budget.

Predicition: you are going to kill the PSU.

The card can max at 150 watts, the CPU is 130 watts (i believe) leaving around 120 watts before hitting max. AMD recommends a 450 watt PSU for this card. I would say its doable but you are at risk.

Does your budget allow for a new PSU?

ya i can try to fit in a PSU. If so, which should i get?

something like this
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Look at ones by Corsair, Antec, Silverstone

The Neo Eco is good too. Less expensive is the Earthwatts, which is also more efficient. The 380W version will have no trouble with up to a HD6850; a HD6770 would be quite comfortable.

i had that same diablotek psu and i needed to upgrade it when i bought my 6770. i didnt want to spend alot and got recommended this antec vp 450. http://www.newegg.com/Product/Product.aspx?Item=N82E168...

that will run a 6770 no problem.

Yes, despite not having active PFC, the VP450 recently tested very well over at HardwareSecrets.