Yeah -- because Apple's price points right now just absolutely suck, and no one is buying their machines.[/sarcasm]
Apple's computers aren't priced any higher than a comparatively-spec'ed Intel- or AMD-based machine. There have been plenty of comparisons of equally-configured Apple/Windows machines, and the Apple machines end up costing roughly the same (+- 5%) as their Windows counterparts. If you take into account the price of the freely included software that comes with every Macintosh purchase (iLife, operating system, etc.), the Macs actually cost less than a similarly-spec'ed Windows machine.
The only drawback to Apple machines is that you can't get less than what they sell. You can't take out the optical audio port if you don't need it, and you can't purchase the computers without a hard drive or RAM installed. That's the only reason bargain-basement crappy home-built systems cost less.
In addition, if your hard drive goes out, who are you gonna call for a warranty repair? Western Digital, of course... and if the video card goes, that's another call to ATi... and if the memory craps out, call Crucial.
If anything goes wrong with your Apple computer, you call Apple. One phone call = multiple problems fixed. Apple, according to Consumer Reports, was ranked extremely high in customer service and repair service. They're not perfect, but nobody is, and Apple is doing many, many things to improve their already stellar customer service.
[/rant]