Also consider your local library for books (and other media I guess). I think a lot of them have some kind of deal set up for ebooks too.
Unfortunately most use Libby/Overdrive which puts DRM on the books and only lets you read through their clunky app or kindle.
There are ways to remove DRM. Maybe there is even a plugin for Calibre which does that automatically.
Also consider your local library for books (and other media I guess). I think a lot of them have some kind of deal set up for ebooks too.
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