Replying to myself, this is not true anymore, for ec2 at least. I think that my comment was upvoted so much really speaks to how chaotic and inconsistent the UI is, because you get a totally different experience using other services.

For instance, I don't see any pricing information when setting up an FSx filesystem, even for the size you setup. And there's definitely nothing saying backups will cost you more than storage (even though they are incremental?)