I have no idea what you're talking about.

For a book, there are per-unit costs of the materials, ink, paper, manufacturing, etc.

For an ebook, these are void. So the cost should be, at the very least, much lower than a physical book. Even if you take into account the effort of writing the book and such, it's an initial cost, so it doesn't justify a high price.

The point being, physical items have costs related to their physicality, digital items don't, so they shouldn't cost as much. It's pretty straightforward.

And to loop back to my initial comment: that's why it's absurd to compare AIs, which are just bullshit for lazy sloppy people, and manufacturing processes, which come from the need to reduce the manufacturing costs of physical items. There is no manufacturing cost of software, so there is no need to mass-produce as fast as possible, and so there is just no reason to let devs throw up slop garbage to go "faster"

Also, on a side note: programming with AIs don't make you code faster, it just increases the amount of bugs and problems with your code. Obviously, since you're just using a nonsense generator to try to produce a complex piece of digital machinery.