Just get a kobo instead. The price difference between with ads and a new kobo is minimal. Not worth the Amazon headache with a locked down device.
Kobo is extremely region limited.
It's fine if it fits your need, but will be far from a good alternative in most regions.
Thing is Kindle hardware is significantly better and cheaper. If you don't mind tinkering get a kindle and jailbreak it to remove ads and add koreader.
I love my Libra 2 reader, but I only use it to read epub files from questionable websites. I would pay for books if they were available as DRM-free epubs.
There are two single line comments recommending kobo over kindle in this thread. How do I know this is a genuine recommendation and not astroturfing?
I have Kobo, but their decision to enable secure boot in newer models, and consequently pushing out FOSS choices as operating systems makes me think I won't get another Kobo. Yes the Nickel menu works still with secure boot enabled devices. I like to think that devices I buy might have different use-case in future, and secure-boot enabled devices seriously harm that.