I have never bought a new system.
I used to get hand-me-downs from friends and family.
My last upgrade was from P233 to 1.3GHz.
The case, power supply, mother board, 1.3 chip w/fan was $300CDN.
My ram, HD, monitor, daughter cards, etc, all fit.

The old 233 would have sold for $50 complete!

Upgrades are cheap and easy.
Just unplug your old stuff, plug it into a new box, and turn it on.
Bill Gates has actually made it all work!