Billing, Pricing, and Support
Pricing Models
Candidates must understand the AWS pricing fundamentals: pay-as-you-go, save when you reserve, and pay less by using more (volume discounts). EC2 pricing options: On-Demand (no commitment), Reserved Instances (1- or 3-year commitment, up to 75% savings), Savings Plans (flexible commitment to a consistent amount of compute usage), Spot Instances (up to 90% discount, can be interrupted), and Dedicated Hosts (physical server for compliance). S3 storage classes: Standard, Intelligent-Tiering, Standard-IA, One Zone-IA, Glacier, Glacier Deep Archive. Data transfer: inbound is generally free; outbound to the internet is charged. AWS Free Tier includes always-free, 12-month free, and short-term trials. AWS Budgets and Cost Explorer help monitor costs; AWS Cost and Usage Report provides detailed billing data.
Support Plans
Know the AWS Support plans: Basic (free, billing and account support), Developer (business hours, email), Business (24/7 phone/chat/email, production guidance, 1-hour response for critical), and Enterprise (15-minute response for critical, TAM, concierge). AWS Trusted Advisor provides best-practice checks; AWS Support Center is where cases are managed.
Traps to Watch
A common trap is confusing Reserved Instances (specific instance family, region, AZ) with Savings Plans (more flexible, apply to any instance family in a region). Another is assuming Spot Instances are suitable for persistent databases: they are not, because they can be terminated with 2-minute notice. Also, data transfer out is the chargeable direction; inbound is free. Finally, Consolidated Billing through AWS Organizations shares volume discounts across accounts.
Worked Example / Rule of Thumb
A company has steady, predictable compute usage for three years and wants maximum savings. Choose 3-year Reserved Instances or Compute Savings Plans. Rule of thumb: if usage is predictable and long-term, reserve; if it is flexible across instance families, use Savings Plans; if it is fault-tolerant and flexible, use Spot.
Key Takeaways
- EC2: On-Demand, Reserved, Savings Plans, Spot, Dedicated Hosts.
- Spot Instances offer up to 90% savings but can be interrupted.
- Inbound data transfer is free; outbound is charged.
- Support plans: Basic, Developer, Business, Enterprise (15-min critical response, TAM).
- Consolidated Billing shares volume discounts; Cost Explorer and Budgets monitor spend.