That is some sound advice. I purchased all the components for this computer through Tiger Direct. The only problem is, a lot of their products come with mail-in rebates. In the end, this is great, but you do need to have the available cash in hand to make the initial purchase.
Before rebates, I paid about $950. After the rebates, the total cost of the computer was just over $500. That was for the tower and all components, 19" LCD monitor, keyboard, and optical mouse. No, I didn't go all out on the accessories. I was more concerned about the actual performance of the computer itsself.
I don't claim to have the baddest computer (it's a few years old now), but when I built it, it was FAR above anything you could buy in the store. Even for the systems that people were paying $2000+ for. Being a few years old, it lags behind many newer models, but it's still crazy powerful for what it is and what it's used for.
When it's time for a new computer, I plan on going the very same route. If you're able to wait the 6-8 weeks for the rebate money, it's the best way to go, IMHO.