So the idea is to upgrade my old PC, from something that would be equal to the first thing that got ever released on Xbox 360, to something more that I can actually call a PC I use for gaming. The idea is still going budget, so no Nvidia GeForce series one billion and a half, please.
System..................Current setup..................................Preferable setup
Graphics card..........Nvidia Geforce 8400 GS 512MB.......Nvidia Geforce 9600 GS 512MB (Around 70$)
RAM.......................3GB..............................................3GB is just fine, I'm not running servers on my machine
Processor................Intel Pentium 4 3.00GHz.................Something dual core clocked at ~ 2.5GHz (around 60$???)
My graphics card is pretty damn outdated, the same applies to my processor. With the graphics cards I'm pretty sure where I want to go - Nvidia Geforce, around 70$-80$ (budget stuff, as I said). The 9600 is a great improvement (frames per second wise) over my current 8400. The price isn't that bad, and I even heard I might be able to use my old video card to some extent.
The real problems start when I'm thinking about changing my processor. I know nearly nothing about processors, so I don't want to get ripped off. The idea is going for a dual core processor clocked at around 2.5GHz. A single core processor just doesn't cut it nowadays. Feel free to leave suggestions regarding the CPU - I have no idea where I'm going myself.