When iPods first appeared, people balked at how expensive they were. Why are they still so expensive, even the older ones? And recently, Apple announced an iPhone, which will be released in a few months, at a price points of $499 and $599. Today on our show to help us figure this out is writer Tim Harford, who recently published The Undercover Economist, a book that demonstrates how ideas of economics can explain every aspect of the world we live in.