I updated my first post:
The following five UK shops sell the same (DRM) book for the exact same amount:
- Foyles
- Waterstones
- WH Smith (Kobo UK)
- Sony
- Nook
[...]
Why do I want to buy EPUB and not convert Amazon's proprietary format back to it?
1. EPUB is just better:
https://ebookglue.com/blog/2013/05/2...kf8-vs-epub-3/
2. My money goes to support EPUB vendors (in the broadest terms), not tricky reconverting to EPUB.