Cost Management and Governance
Cost Management and Governance tests pricing mechanics, cost visibility, multi-account governance, and support entitlements. Questions usually contrast two tools that sound similar - Cost Explorer versus Budgets, or the Pricing Calculator versus the TCO Calculator - or ask what an Organizations feature actually does.
Pricing mechanics
AWS bills on pay-as-you-go for most services, with data transfer out and cross-AZ traffic as recurring hidden cost drivers. Discount instruments: Reserved Instances and Savings Plans for steady-state compute (up to roughly 72% for EC2 Instance Savings Plans and Standard RIs, about 66% for Compute Savings Plans), Spot for fault-tolerant work (up to 90%). The Free Tier mixes always-free allowances, 12-month offers, and short trials. Per-second billing applies to Linux instances with a 60-second minimum; some services bill per hour, per GB, or per request.
Cost visibility
Cost Explorer visualizes spend and forecasts, and drives Savings Plans recommendations. AWS Budgets sends alerts or triggers actions when actual or forecast spend crosses a threshold. The Cost and Usage Report is the most granular line-item dataset, delivered to S3. Cost allocation tags split spend by team or project; activation is required before tags appear in billing reports. Compute Optimizer rightsizes instances from utilization data. The Pricing Calculator estimates the cost of a planned architecture, while the TCO Calculator compares an on-premises estate against AWS.
Governance
AWS Organizations provides consolidated billing, which pools usage for volume discounts and shares Reserved Instance and Savings Plan benefits across member accounts. Service control policies restrict what member accounts can do - they filter permissions and never grant them. Control Tower sets up a landing zone with guardrails; AWS Config and CloudFormation Guard support policy-as-code enforcement.
Support plans
Basic has no technical support. Developer adds business-hours email. Business adds 24/7 phone, chat, and email with a one-hour response for production-down cases and full Trusted Advisor checks. Enterprise On-Ramp offers a TAM pool and a 30-minute business-critical response. Enterprise adds a designated TAM and a 15-minute business-critical response.
Worked example
A company runs 30 Linux instances continuously for three years and wants the lowest compute bill with predictable usage. Reasoning: On-Demand wastes the commitment opportunity and Spot risks interruption. A 3-year all-upfront Standard RI or EC2 Instance Savings Plan captures the deepest rate for a known family and Region, while Compute Savings Plans would be the choice if the family or Region might change. Consolidated billing across the organization's accounts then pools that usage so discounts apply wherever the instances run.
Traps that cost marks
- Using the TCO Calculator for a greenfield AWS design - that is the Pricing Calculator's job.
- Expecting SCPs to grant permissions.
- Assuming tags appear in billing reports without activation.
- Forgetting data transfer and cross-AZ charges when estimating cost.