I'm not entirely sure, but I don't think that record labels work by increasing the price of the CD in relation to how few albums have been sold.
The truth of the matter (or what I have skimmed off of Dig!) is that major labels lose money on nine out of ten albums released and only recoup on the big sellers, the 50 Cents and the new Good Charlottes of the world. The way the bands get payed (from what I can remember from So You Wanna Be A Rock and Roll Star) is that they are given an advance, and from there the money they get from albums is minimal unless they are able to sell enough records to recoup the money they spent on recording and mastering and doing videos.
They also get some money from tours and merch.
Of course, that's with majors. It's a whole different ball game with independant labels, I assume.
The problem with just going the CD-R route is that you don't have the distribution network. You can sell at shows and over the internet, but your local HMV isn't going to be putting your album out anytime soon at that rate. Plus, I own a few albums that were only released on CD-Rs, but on the whole, I need a product that has a bit more polish than a bunch of guys at home with their computer, and there are others as well.
CD-Rs are a good way to start out. Devendra Banhart was discovered while selling CD-Rs of his music after one of his sets. But they don't work in terms of careers.