Economy of scale

Isn't economy of scale amazing? I just bought this set of books for thirty-seven pounds (fifty bucks). They are small, but there are twenty of them! If I published a small picture book, probably I'd have to sell just that one for a similar price, but because the good doctor is hugely popular, the price per unit goes way down.
Of course, that is also the only reason we can buy insanely complex objects like cameras or iPods at prices anybody can afford. If there were only ten customers in the world for an iPod, the price would have to be in the millions.

(The iPod is included for scale, it didn't come with the books!)