Think of it as the "paying for a designer label" concept. Some people will shell out tens of thousands of dollars for a Ferrari or other "exotic" sports car while others think a Kia Rio is just as good because they both do the same thing, take you from point "A" to point "B".
I have only read one book from King, It was his first attempt at a fantasy novel. He is definately a good writer, but there is no way I would pay $17 or $25 for an ebook that can be had for $8 in paperback form, but some will. Like you, I do not have a way to read amazon ebooks on a portable reader.