Common AWS Cost Mistakes (And How to Avoid Them)

AWS offers incredible flexibility, but that flexibility is also why cost surprises happen. Many organizations believe their environment is “optimized” simply because they use Savings Plans or tagging—but cost risk often lives elsewhere.

1. Relying Only on Savings Plans or RIs

Savings Plans reduce compute cost, not architectural waste. Overprovisioned EKS clusters, oversized EC2 volumes, and unused NAT gateways can quietly consume thousands per month.

2. Not Turning On Detailed Billing Exports

The Cost & Usage Report (CUR) is the single source of truth. Without CUR-based analytics, organizations rely on incomplete summaries and miss hidden charges.

3. Ignoring Data Transfer Patterns

Inter-AZ, inter-region, and public egress charges are usually the biggest source of “mystery spend.” Most of this is avoidable with architectural review.

4. Underestimating Managed Services

Services like OpenSearch, SageMaker, and Redshift often scale themselves in expensive ways. Even medium environments can exceed expectations if left untuned.

5. Not Automating Daily or Weekly Alerts

Cost anomalies rarely appear at month end — they appear as soon as something scales unexpectedly. Automated alerts make surprise invoices preventable.

Summary

Most AWS cost problems stem from design drift, unmanaged automation, or lack of visibility. With the right telemetry and alerting in place, nearly all can be avoided.