If anyone has personally built a computer, what did those parts run you, and what quality parts did you use?
I've built about 20 for friends, family, and myself over the past dozen years. Yes, I was ordering out of Computer Shopper back when having graphics on web pages was high tech. Nowadays I tell people that unless they have very specific needs for their components, they're better off just buying a retail system. For instance, I want my PC to be as quiet as possible, so I hunt for particular components by reading silentpcreview.com. (1.5 pound fanless heatsinks FTW.)
Too many people get wrapped up in the search for components without asking themselves what they want to get out of them. If what you want is primarily a gaming rig, that's very different than something used primarily for video editing, or whatever else. So first figure out what you want to do, then try a forum like hardocp (esp. for gaming) or ars technica and they can help you build exactly what you need. But if all you want is just some generic computing power, you might think about getting a laptop.
Last bit of advice: if you're going to skimp on quality anywhere, do it in the case. Cases are easy to replace. Absolutely do not skimp on the RAM, PSU, or motherboard. Save money without sacrificing too much power by finding whatever the present best overclocking chips are. Even if you aren't overclocking, it's generally better to buy from the low end of the GHz scale for any particular core, as they generally represent a better value.