There’s certainly some validity to this explanation. Yes, those charts and diagrams are expensive to produce, and the relatively small print runs of textbooks keep publishers from enjoying the kind of economies of scale they get on a bestselling popular novel. Any economist who has a pulse (and probably some who don’t) could poke holes in this argument pretty quickly, though.
In the simplest economic terms, the high price of textbooks is symptomatic of misaligned incentives, not exorbitant production costs. Students hold the reasonable stance that they’d like to spend as little money as possible on their books. Students don’t really have the latitude to pick which texts they need, though.
Read the real story behind sky-high textbook prices at mental_floss. Link
As the master said: "very few people spend other people's money as carefully as they spend their own".
When you are making the selection of something to purchase that benefits you, but the bill is to be paid by others, that causes quality to be weighted much more highly in the decision than price.
This is definitely not the reason the cost of books is so high, but it's part of the problem. Another problem is the teachers requiring the latest edition of the texts. You might find a 2008 version of the 2011 text for ten or fifteen bucks, about a tenth of the price. The content of the text is not that different, so there's no reason to require the newest version each year. Especially in certain subjects, which don't change that much from year to year.
But I have to read this...sure, and later your boss will want you to read his every memo. Will you, dweeb? Three-point-oh-and-go! Life's too short.
Textbooks in the US are so expensive because we have such an insane financial aid program. Countries without massive giveaways to students (the UK, France, Sweden, etc.) have much cheaper books (and tuition as well.)