Another vote for the Pocketbook (~€100 on online stores in Europe). As the parent above, I never connected it to the internet, not once. I use a USB cable to add new books. The Pocketbook is also recommended by Mozilla's Privacy Not Included list as the most privacy-friendly e-reader. I wrote a blog post about my Kindle → Kobo → Pocketbook experience: https://suffix.be/blog/search-perfect-ereader/