Very interesting article. I think it can even be extended to other kinds of software.
I've faced this question on the App Store, which is, of course, a totally different market My experience is that pricing an in-app purchase at 0.99$ or 1.99$ does not change anything as long as it brings a significant added value to the app.
It clearly is important not to lower our prices too much. I think the TV industry (Panasonic, Sony...) should be a reminder that we can not indefinitely lower prices.