Buying a new PC, need advices from computer geeks

[French jurist]

Hi,

Well, I'm about to buy a new PC.
I don't need a quadcore, but I want a Core 2 Duo (better than a dual core from what I've read).

Since it will be used too for gaming purposes (I'm 40, shame on me), I want to buy too a good mid range video card.

All in all, I want the best bang for the bucks.

As far as now I may eventually decide myself for this machine :
http://articulo.mercadolibre.com.ar...reduo-e5400-27ghz2gb-nueva-ddr3320gbvideo-_JM
(I'll change the power supply for the video card, I don't need the monitor so the price will be lowered by 850 pesos).

Question : on mercadolibre is it the best deal for a core 2 duo ? Something I am missing ?


***


For the video cards, my choice has landed onto this special promotion (usually sells for 50 more dollars here) :
The GTS250
http://articulo.mercadolibre.com.ar...ts-250-1024mb-256bit-ddr3-pci-e-1-gb-box--_JM

Eventually I could opt for the HD4850 (but it seems the GTS250 is better)
http://articulo.mercadolibre.com.ar...ti-radeon-hd-4850-1gb-ddr3-dual-dvi-pci-e-_JM

Eventually again, I could add 50 bucks and go for the Ati 5770 with 1GB of DDR5 :
http://articulo.mercadolibre.com.ar...70-1gb-ddr5-vapor-x-el-ultimo-modelo-dx11-_JM

Question : is my choice (GTS250) the best money wise or is it worth it going for the 5770 ? Any other video cards I may have missed ?


Thanks !