I posted on your previous post, so I'll just copy and past it. You will be absolutely fine because I have a 7870 with a 3570k with a CX430 Watt power supply. You could probably have 2 way crossfire with your graphics card because it only takes up 130 watts. 130 + 106 + 10(hdd) + 2(ssd) + idk about the 24pin so lets just say 150 watts there. So in total your machine is probably using around 300 watts at full load. I could be totally wrong with the 24-pin thing but if I'm not then yea...
For a system using a single ASUS EAH6850 graphics card AMD specifies a minimum of a 500 Watt or greater power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 25 Amps or greater and have at least two 6-pin PCI Express supplementary power connectors.
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Sufficient Total Combined Continuous Power/Current Available on the +12V Rail(s) rated at 45°C - 50°C ambient temperature, is the most critical factor.
The Corsair Builder Series CX600 V2 (CP-9020048-??), with its maximum combined +12 Volt continuous current rating of 46 Amps and with two (6+2)-pin PCI Express supplementary power connectors, is way more than sufficient to power your system configuration with a single ASUS EAH6850.
You can skip few lunches, make something at home, and you save at least $40 a week in few months you have enough for a good VGA and some flowers for your wife
You can also try luck on ebay. You can get preaty good deals. I sold my 6950 for $140 and my 7950 for $250. Now I'm running 7970 w boost I bought for $359 after rebate...so I actually made some money upgrading.