Notes from the team building C3X. Cost estimation for Terraform, the economics of cloud infrastructure, and how to ship FinOps tooling without a SaaS gate.
Route 53 health checks cost $0.50 per month for AWS endpoints and $0.75 for external ones, with optional features adding $1 to $2 each. On their own they are cheap, but dozens of them with add-ons quietly add up. Here is the pricing.
CloudWatch Logs charges about $0.50 per GB to ingest and only $0.03 per GB per month to store, so ingestion, not retention, is almost always the bigger bill. Understanding the split changes how you cut logging cost. Here is the breakdown.
CloudWatch dashboards cost $3 per dashboard per month after the first three free, and API calls to render them add more. Teams that auto-generate a dashboard per service can rack up an unexpected line. Here is how dashboard pricing works.
AWS KMS charges $1 per month per customer-managed key and $0.03 per 10,000 requests, so a few keys is trivial but a high-throughput app making millions of encrypt and decrypt calls can flip the bill to requests. Here is how to tell which side dominates.
Transit Gateway inter-region peering lets you link regions through the AWS backbone, but you pay per-GB data processing on each side plus cross-region data transfer. For high-volume inter-region traffic the fees stack. Here is the cost breakdown.
Direct Connect adds port fees but slashes data transfer out to about $0.02 per GB versus $0.09 over the internet. For heavy, steady egress to your data center the savings can dwarf the port cost. Here is the break-even math.
Global Accelerator charges a fixed $0.025 per hour plus a per-GB premium, while CloudFront has no fixed fee and bills per GB and per request. They solve different problems, and picking the wrong one wastes money. Here is the cost comparison.
VPC Flow Logs are free to enable, but you pay to deliver them: about $0.50 per GB to CloudWatch Logs or less to S3. On a busy VPC that ingestion cost can surprise you. Here is how flow log pricing actually works.
CloudTrail management events are largely free, but data events cost $0.10 per 100,000 events, and high-volume S3 or Lambda logging can generate billions of them. Here is how data event pricing works and how to keep it in check.
AWS now charges about $0.005 per hour for every public IPv4 address, in use or idle, adding roughly $3.65 per month per address. For fleets with hundreds of public IPs the total is real. Here is how the charge works and how to cut it.
SSM Parameter Store standard parameters are free, while advanced parameters cost $0.05 each per month and higher-throughput API calls carry a fee. Knowing when you actually need advanced tier saves money over Secrets Manager. Here is the pricing.
Traffic between resources over private IPs in the same AZ is free, but the same traffic over public or Elastic IPs is charged even within a region. Using the wrong address turns free traffic into a per-GB bill. Here is how to keep it free.
Most Azure VM bills carry oversized instances that never touch their allocated CPU or memory. Right-sizing to the correct family and size, then layering reservations, is the highest-return Azure cost move. Here is how to do it.
Azure SQL Database serverless bills compute per second and pauses when idle, which can slash the bill for intermittent workloads but cost more for steady ones. Here is where serverless wins and where provisioned vCore is cheaper.
Azure SQL elastic pools let many databases share a single pool of DTUs or vCores, which is far cheaper than provisioning each database on its own when their peaks do not coincide. Here is how the math works.
Cosmos DB autoscale raises the per-RU/s rate by 50 percent but scales throughput automatically between 10 percent and 100 percent of a maximum. For variable traffic it can be cheaper than standard provisioned; for flat traffic it is a needless premium. Here is the math.
The redundancy option you pick for an Azure storage account changes the price of every gigabyte. LRS is the baseline, ZRS adds zone resilience, and GRS roughly doubles cost for cross-region durability. Here is what each buys and costs.
Azure Blob Storage charges not just for gigabytes stored but for every read, write, and list operation, and on cool and archive tiers those transaction fees can dwarf the storage itself. Here is how transaction pricing works and how to control it.
Azure Monitor spans metrics, alerts, and Log Analytics ingestion, and the ingestion charge at roughly $2.30 per gigabyte is what usually runs the bill up. Here is how each part is priced and how to keep observability affordable.
Application Gateway v2 bills a fixed hourly fee plus capacity units that scale with traffic, and the WAF-enabled SKU costs noticeably more. Here is how the pricing works and when a simpler load balancer is cheaper.
AKS offers a Free control plane with no uptime SLA and a Standard tier that charges about $0.10 per cluster per hour for a financially backed SLA. Here is when the paid tier is worth it and where the real AKS cost actually lives.
Virtual Machine Scale Sets come in Flexible and Uniform orchestration modes. Neither mode has an orchestration fee, but Flexible's ability to mix spot and on-demand and different VM sizes changes what you can save. Here is the cost angle.
B-series burstable VMs cost far less than general-purpose sizes because they run at a low baseline CPU and bank credits for bursts. For mostly idle workloads they are the cheapest option; for steady load they throttle. Here is how they work.
The Dv5 general-purpose and Ev5 memory-optimized families share a CPU generation but differ in memory per vCPU and price. Choosing Ev5 for a CPU-bound workload pays for RAM that sits unused. Here is how to pick the right family.