If you want to go for the Econobox config I'd highly recommend to at least switch in these parts for those listed:
Phenom II x4 940 4x3,0 GHz
* Actually $5 cheaper than the Athlon (plus Phenom is supposed to be the superior architecture)
GeForce GTX 460
* Only $25 more expensive and up to 30% faster
Seasonic 430W Power Supply
* As Phenom and GTX460 draw more power the 380W PS seems a bit low
The Econobox components would cost about $570 right now, after these changes it would be about $610...
and I would then still switch the memory for a
4GB kit as 2GB may not be enough for more demanding games anymore.
That would be $630 then and for everything below that you will cut away quite some performance imho.
Link for $610 System with 2GB memory
Link for $630 System with 4GB memory