"This price was set by the publisher"
@Chris Gray: Yes, some Kindle books ARE more expensive than paper- or in some cases, hard-back. Why? Well, you'll see on Amazon's page for them, the little phrase "This price was set by the publisher".
In other words, the reason the price is high is because of the cartel that Apple et al are running. Amazon can't sell them as cheap as they want to.
In fact, the precise point of the El Reg article. :)