They sold me a counterfeit Horowitz and Hill [0], since it was outside of the return window the support person basically said, "you have an interesting memento".
[0] https://artofelectronics.net/the-book/counterfeit-editions/
[0] https://artofelectronics.net/the-book/counterfeit-editions/
If it is a counterfeit, it is flawless as far as I can tell. It has none of the physical problems listed on that link. They only thing suspicious is the price.
I've only bought ~10 Kindle books over the years because DRM, but had been getting more open to it. Then just recently they started delivering ads to the iPad reader as 'notifications' with a red icon that won't go away until you tap to see. They may think that's a minor new feature which they only use occasionally, and which their average user will appreciate. But to me it looks like the start of "I am altering the deal. Pray I don’t alter it any further."
Check out your library system. My library has an amazing selection of books, usually available in EPUB and Kindle formats. If you live or work in New York State, you can get library cards in many libraries including NYPL. NYPL also lets you access Brooklyn.
What about the non-technical user who disputes a charge, doesn't even know what DRM stands for, and finds themselves in this situation?