I paid my student debt, these kids don't deserve any handouts!

Boomers who paid tuition and living costs that were a manageable fraction of their part time student job that doesn't even fucking exist anymore.

Same reason as the rest of college being expensive. The can charge whatever they want because the government will loan the money to pay for it.

Low volume and high costs mainly. The printing costs are dwarfed by all the writing, proofreading, layout, editing etc that goes into them. The $300 ones tend to be these massive books with a thousand pages of instruction, problem sets, images, infographics, etc. None of these books are selling a billion copies like 50 Shades of Grey either. The most famous textbooks maybe, but a lot of them would be lucky to sell a thousand copies.

And of course, yes, greedy giant publishing companies. But those companies publish books for many different courses and professors, plus I think they own academic journals as well (which make them way more money and cost way less to publish than textbooks do).

Cause all the professors are trying to supplement their income and publishers are also greedy vultures.