Textbook publishers aren't improving their offerings with each iteration. They re-release the same shit with a different cover and charge schools (and taxpayers) a premium for this "service." In some cases, the content they republish was already paid for with taxpayer money. Their business model is exploitative on every level. Fuck them.
A fiction author puts effort into a work of art. They're not forcing sales or doing anything shady; they're just someone trying to make a living selling copies of their art. Respect that and don't play games with them, unless they can't be civil.