Building my own PC is one of those things I should have done years ago (I've been a computer/PC professional for over 20 years now), but never got around to.  But when I compared the price of building my own vs. buying one with the same specs, it turned out that building it myself cost me 1/2 what an equivalent commercial model would.  So for around $1k, I now have a machine equivalent to a Dell XPS 720, and actually better, because: 1) it has a newer Intel Core Duo CPU that just came out in January, is faster and less power-hungry than existing Core Duos, and is still kinda hard to get, and 2) still has Windows XP, since I just brought it over from my old machine. No Vista for me.