AWS NAT Gateway bills have two main charges: a low hourly fee and a data-processing fee. The data-processing charge, $0.045 per gigabyte, is the primary cost driver and compounds with traffic. To reduce these costs, several strategies can be employed, starting with the most impactful.First, implement free gateway endpoints for S3 and DynamoDB, as this often eliminates 30-60% of the per-gigabyte charges. Next, consider interface endpoints for frequently accessed AWS services. VPC Flow Logs are crucial for identifying high-traffic sources, with fixes often involving caching and better hygiene.To avoid cross-Availability Zone surcharges, route traffic zonally or consolidate gateways deliberately. Consolidating non-production NAT gateways can save on hourly fees for unused resources. For further savings, a NAT instance, like fck-nat, can entirely eliminate the per-gigabyte fee, though it requires managing operations.A flat-priced Network Virtual Appliance (NVA) with egress filtering offers managed replacement for the NAT Gateway, killing the per-gigabyte charge and acting as a firewall. The choice between these solutions depends on traffic volume and operational capacity. The per-gigabyte data-processing charge is typically the most significant cost to address, rather than the hourly fee.