Apple's market share continues to rise even with the "high prices" you mention. Don't forget that PC-makers cut a lot of corners when making those budget systems. They'll find some startup company to buy DVD drives from or ask their grandma to make the motherboard.
After years and years of building my own PCs because it seemed cheaper and was pretty fun to do (if you were successful), I don't mind paying the little bit extra for the Apple stuff THAT JUST PLAIN WORKS. There are slight quirks that pop up from time to time, but there isn't mind-numbing $#@% that makes me want to take a long walk off a short pier.
While I think my mom's new Dell isn't that bad of a computer at $600, it's still not a Mac. The OS is still made by Microsoft, I would've had to pay another $80 for built-in 802.11n wireless (I ended up finding a $6 802.11g card...score!). Sharing stuff over a network is NOWHERE NEAR AS SIMPLE. It's hard to compare a mid-tower to anything Apple makes, but both seem to be decent deals for the users.
So basically I don't think Apple is ignoring their computers too much. I'm miffed at the apparent lack of movement on Blu-ray adoption, but that may change soon. Other than that, I can't say too much bad about them. Apple has its fair share of problems, but they don't have anybody else's share as well.