In order for us to judge if it is a good buy u have to elaborate what the machine would be mainly used for. If just gaming the better move for the green i would say is just
955BE
any 8/8 Cfable mobo with reasonable clock capability
HD 6950
700-750w 80+ psu
just the 4GB DDR3
What i can say though is huge negative on that TT TR2 750 @@
Review
Thermaltake TR2 RX 750 W is, according to our methodology, a flawed product that must be avoided at all costs. It can't deliver its labeled wattage at high temperatures, but this is not the worst of it: ripple and noise level are way above the maximum allowed when you pull 80% or more from the unit's labeled capacity (i.e., 600 W and above), overloading your components (especially electrolytic capacitors from the motherboard and video cards), which can cause your PC to present an erratic behavior (crashes and random resets) and, under extreme conditions, damage components.
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My El Cheapo move to better PC Audio!
http://forums.amd.com/forum/messageview.cfm?catid=13&threadid=153336&enterthread=y