A couple of years ago I started with this bare bones PC kit.
MotherBoard - Asus M2N68-AM SE2 µATX Motherboard
Processor - AMD Athlon II X4 620 2.6GHz
Ram - 2GB Ultra PC5400 DDR2 667MHz Memory
And other assorted parts, case, power supply, hard drive etc.
I slowly upgraded to this.
MotherBoard - Asus M4N68T-M V2 µATX Motherboard
Processor - AMD Phenom II X4 980 Black Edition Deneb 3.7GHz
Ram - 8GB 4GB X 2 Kingston PC10600 DDR3 1333MHz Memory
Video - NVIDIA Geforce GT 220 1024 Meg PCIe
I bought the video card first, then the M4N68-AM SE2 and DDR3. The M4N68 let me use my old Athlon II and all the other parts from the bare bones kit. Now that I've upgraded just about everything else I have two PC's. The original bare bones kit and what I'm using now thats in my profile. I went the way I did because money is tight and I have to buy things in dribs and drabs. My system is nothing to brag about but it does what I want. I can play all the games I like and run the programs I need.
There are always options.