cas123

What money is the 4000? (RMB, HKD or ?)
Are you using any old hardware(from your old system)?
Does the price include monitor and software(OS)?
What resolution do you usually play game at (720p, 1080p or more)?
And what kind of game?

Anyway: price from newegg cn(RMB)
CPU: i5 2300
MB: Gigabyte p67a-b3-b3
Ram: 2x A-Data DRR3 2gb 1333
Video Card: HD5770 or GTS 450 DDR5 1GB
DVD: Sony AD-7260s
Case: CoolerMaster RC-370-KKN1
PSU: CoolerMaster RS-460-asaa-d3
Total: ~4200 + little more for a hard rive
Should be good upto 1920x1080(medium to high quality setting depend on game) resolution in most games.