Looking to upgrade my system wondering where to start

[ramulux]

My current set up is getting kind of old and I want to start upgrading it but I have a limited amount of money and will only be able to start off with a part or two.
Here is my current build

CPU- Intel E5200 2.5 ghz
GPU - Radeon HD 4670
Motherboard - Gigabyte GA-EP45-DS3L
RAM - G.Skill 4 gb
Hard Drive - Seagate 250 gb
Power Supply - Rosewill 500 watt

Where should I start upgrading if I will only be able to buy a part at a time? You could probably consider this a budget build price range maybe a little higher.

 

[gkay09]

^ Buy a graphic card and PSU first,...
If you are fine with overclocking, then you should easily be able to overclock that E5200 to say 3-3.5GHz with an aftermarket cooler easy,...
You can reuse the Graphic card, PSU and the CPU cooler for your future builds,...

 

[ramulux]

What would be a good reasonably priced PSU? Also, would I be able to get a new hard drive to use in my current system and also in my next one?

 

[gkay09]

^ If you will be using just a single graphic card, then a high-quality 500-550W PSU would be good,...
From any of these manufacturers - Corsair/ Antec EA or TP or ECO Series/ OCZ ModeXtreme or Fatality series/ Seasonic/ Silverstone/ Cooler Master Real Power or Silent PRO/ XFX...

 

[ramulux]

Would I be able to put a hard drive like this into my current build and then use it again after I upgrade my CPU/Mobo and stuff?

Western Digital Caviar Black 640 gb
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136319

Or what might be a better hard drive at around that price?

 

[rvilkman]

Samsung Spinpoint F3 1TB $64.99

Bigger and faster, generally the default recommended drive on these forums

 

[gkay09]

^+1 for that Samsung F3, actually its $59.99 now,...
And yes you can reuse the HDD, but when you change the Mobo and CPU, you would have to re-install the OS,...