I'm not trying to debate whether an ebook or a physical book is better or worse and I feel like most in this thread have willfully misinterpreted that. My point was that if you consider just the cost of a good, you are likely to run into "how can this possibly be fair" scenarios. But cost isn't the only thing that factors into price, whether you like the good or not.

Ebooks and physical books have different uses, different distribution, different benefits, different downsides. They aren't identical and it's not surprising or unfair that they're priced differently.