Brand New Built or Upgrade?

[Des123]

Approximate Purchase Date: Within the next month

Budget Range: 400-500

System Usage from Most to Least Important:gaming, surfing the internet, watching movies

Parts Not Required: keyboard, mouse, monitor, speakers, OS and Cooler Master 650W PSU

Preferred Website(s) for Parts: http://www.msy.com.au/default.jsp?

Country: Australia

Parts Preferences: Intel, CoolerMaster, Thermal take

Overclocking: Maybe

SLI or Crossfire: No

Monitor Resolution: 1680x1050

Additional Comments: Need a New Case

My Current Specs are:

Intel Core 2 duo E6750 @2.6 Ghz
GA-P35-DS3L
Geforce GTX 465
DDR2 Corsair 2GB (1GBx2)
WDD Caviar 465GB
CoolerMaster 650W PSU

Am I better off Buying a new case (need help deciding http://www.msy.com.au/default.jsp?category=42) , overclock to around 3.00Ghz (Never overclocked before) and 4GB of Ram = Around $150 or just buying a whole new build entirely?

ASUS P8P67-LE-V3 DDR3 Intel 1155pin Motherboard - $115
Intel Core i5-2500K 3.3Ghz 1155pin Boxed CPU - $220
G.Skill Ripjaws X F3-10666CL9D-8GBXL 8G Kit(4Gx2) DDR3 1333 - $53
GTX 465
Coolermaster 650W PSU
New Case
Total- $388 and lets say $100 for the case

 

[cutebeans]

Get a z68 motherboard.

If I were you I'd just get a $40-$70.