I don't think Apple have any interest in selling something at lower price points, because like Sony, Porsche etc. their brand is of a better quality product which of course should cost more.
SGI, Sun, HP all used to sell high end workstations at the top the market (~2-20x more than what Apple charged at the time) - that market got eaten by PCs when they couldn't differentiate anymore. Unlike those high end machines, Apple has no performance advantage over PCs. Apple's only real difference is the OS.
Apple's emerging threat is Linux/Open Source, which has many of the same advantages OS X over Windows does and of course was good enough for Apple to take a kernel, browser and printing system from. Linux/Open Source doesn't have to be better than OS X - it just has to be better than Windows and good enough that people don't want to spend extra on a Mac.
Edit: this is classic "The Innovator's Dilemma": http://en.wikipedia.org/wiki/Disruptive_technology