Every RPO and RTO target in your DR plan has a line item attached to it. A 15-minute RPO costs a specific amount per month. A 5-minute RPO costs roughly twice that. Most teams discover these numbers on their cloud bill , not during architecture review.

This piece works through the cost structure of each DR tier, using a representative 3-tier application as the base case. By the end you will have a model you can apply to your own workload.

Your RPO Is a Price Tag, Not a Policy

RPO and RTO are often treated as compliance checkboxes, agreed in a governance meeting and forgotten until an incident. They are actually financial commitments. Honoring a 5-minute RPO on a write-heavy PostgreSQL database costs real money every hour the database runs.

The cost driver is replication.…