[desiibond]

Since you don't play much of games, try this:

1) C2D E7200 : 5.5k
2) XFX 630i : 3k-3.5k

or

2) MSI P45 Neo-F for 5.5k + 9500GT for some 5k

8k-9k

Get a 9500GT or HD4670 if necessary. The onboard GPU on 630i is good enough to run AOE3.

You said you have DDR2 RAM 4Gb.