If you have deduplication-enabled Storage Policies that are using an AWS S3 Infrequent Access tier or an Azure Cool Access tier (either directly, or via Combined Storage Tier configuration), there is potentially an opportunity to optimize your cloud storage costs by reviewing the associated DDB backup configuration.
Noting that AWS Infrequent Access Tiers and Azure Cool Storage Tiers have a 30-day minimum storage duration, and that DDB backups are generally performed daily but only retained for 0 Days / 1 Cycle, it is more cost-effective to use S3 Standard / Azure Hot Access tiers for those DDB Backups.
For example:
100GB (DDB Backup) x $0.023 (S3) x 2 (accounting for once-daily data aging) = $4.60 per Month.
100GB (DDB Backup) x $0.0125 (S3IA) x 30 Day Minimum Storage Duration = $37.50 per Month.
For smaller environments it may not be worth the effort to change anything, but with our DDB Backups to S3IA exceeding 1.5TB, we are looking at an annual cost reduction of ~$6000.