https://aws.amazon.com/rds/mysql/pricing/?pg=pr&loc=2проверил, пока ничего не поменялось:
There is no additional charge for backup storage, up to 100% of your total database storage for a region. (Based upon our experience as database administrators, the vast majority of databases require less raw storage for a backup than for the primary dataset, meaning that most customers will never pay for backup storage.)
◦ For example, if you have an active MySQL DB instance with 500 GiB-month of provisioned database storage and an active PostgreSQL DB instance with 200 GiB-month of provisioned database storage, we provide up to 700 GiB-month of backup storage at no additional charge.
◦ Multi-AZ and Single-AZ configurations are treated the same from a backup storage perspective.