The fact that paperback and sometimes hardcover books are cheaper than ebooks is just wrong. The costs of distribution are negligible for ebooks.
When I see an ebook that I like (that isn’t time sensitive) and it is over $10, I put it in a list that I have on Amazon. I periodically revisit the list to see if anything has dropped below $10. The good news is that sometimes they do. The bad news is that sometimes I no longer care – so the publisher and author lose out on the revenue from me forever.
Note: My wife and I have over 700 ebooks in our library – we are power buyers.
https://www.vox.com/culture/2019/12/23/20991659/ebook-amazon-kindle-ereader-department-of-justice-publishing-lawsuit-apple-ipad