Cost Estimation
Purpose
Estimate infrastructure costs, operational expenses, and total cost of ownership to support budget planning and architecture decisions.
When to Use
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Architecture planning
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Budget approval
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Scaling decisions
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Cost optimization
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Vendor comparison
Prerequisites
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Infrastructure design defined
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Expected usage patterns
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Cloud provider pricing
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Operational requirements
Process
Step 1: Identify Cost Components
Categories:
- Compute (VMs, containers, serverless)
- Database (instances, storage, backup)
- Storage (object, block, backup)
- Network (transfer, CDN, load balancer)
- Third-party services
- Licenses
- Operational (monitoring, logging)
Step 2: Estimate Usage
For each component:
- Baseline usage
- Growth rate
- Peak vs normal
- Seasonal variation
Step 3: Calculate Costs
For each component:
- Unit cost (from pricing)
- Estimated units
- Monthly cost
- Annual cost
- Growth projection
Step 4: Consider Optimizations
Cost reduction options:
- Reserved instances
- Spot instances
- Right-sizing
- Auto-scaling
- Caching
- CDN
- Storage tiers
Step 5: Create Cost Model
Model includes:
- Itemized costs
- Monthly totals
- Annual projections
- Growth scenarios
- Optimization opportunities
Inputs
Input Type Required Description
infrastructure_design Markdown Yes Architecture
usage_projections JSON Yes Expected usage
pricing JSON Optional Provider pricing
Outputs
Output Type Description
cost_estimate.md Markdown Detailed estimate
cost_model.xlsx Spreadsheet Calculations
optimization_recommendations Markdown Cost savings
StudyAbroad-Specific Considerations
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Document storage grows linearly
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Peak costs during deadline periods
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External API costs (if metered)
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GDPR compliance may add costs
Integration Points
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DevOps Agent: Infrastructure implementation
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Operations Agent: Cost monitoring
Examples
Cost Estimate - StudyAbroad-v1 (AWS, EU-WEST-1)
MONTHLY COST BREAKDOWN:
COMPUTE:
| Component | Spec | Qty | Monthly |
|---|---|---|---|
| API (ECS) | 0.5 vCPU, 1GB | 2-10 | $80-400 |
| Workers | 0.5 vCPU, 1GB | 1-5 | $40-200 |
| Average | $180 |
DATABASE:
| Component | Spec | Qty | Monthly |
|---|---|---|---|
| RDS PostgreSQL | db.t3.medium | 1 | $100 |
| RDS Storage | 100GB | 1 | $25 |
| Read Replica | db.t3.small | 1 | $50 |
| Backup | 100GB | 1 | $10 |
| Total | $185 |
CACHE:
| Component | Spec | Monthly |
|---|---|---|
| ElastiCache | cache.t3.micro | $15 |
STORAGE:
| Component | Spec | Monthly |
|---|---|---|
| S3 (documents) | 500GB | $12 |
| S3 (requests) | 1M req | $5 |
| CloudFront | 100GB transfer | $10 |
| Total | $27 |
NETWORK:
| Component | Monthly |
|---|---|
| ALB | $20 |
| Data Transfer | $30 |
| Total | $50 |
OTHER:
| Component | Monthly |
|---|---|
| Secrets Manager | $5 |
| CloudWatch | $20 |
| Route53 | $5 |
| Total | $30 |
SUMMARY:
| Category | Monthly | Annual |
|---|---|---|
| Compute | $180 | $2,160 |
| Database | $185 | $2,220 |
| Cache | $15 | $180 |
| Storage | $27 | $324 |
| Network | $50 | $600 |
| Other | $30 | $360 |
| TOTAL | $487 | $5,844 |
With reserved instances (1yr): ~$4,200/year Peak months (add 50%): ~$730/month
GROWTH PROJECTION:
| Year | Users | Monthly Cost |
|---|---|---|
| Y1 | 5K | $500 |
| Y2 | 15K | $800 |
| Y3 | 30K | $1,200 |
Validation
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All components included
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Pricing is current
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Usage estimates reasonable
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Growth scenarios modeled
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Optimization identified