/cost-estimator

name: cost-estimator
description: Infrastructure and development cost estimation for technical projects. Use when planning budgets, evaluating build vs buy decisions, or projecting TCO for architecture choices.

Cost Estimator

Provides frameworks for estimating infrastructure costs, development effort, and total cost of ownership (TCO) for technical projects.

When to Use

• Planning infrastructure budgets
• Evaluating build vs. buy decisions
• Projecting costs at different scale points
• Comparing technology options by cost
• Creating business cases for technical investments

Cost Categories

Total Cost of Ownership (TCO)

TCO = Infrastructure + Development + Operations + Opportunity Cost

┌─────────────────────────────────────────────────────────────────┐
│                    TOTAL COST OF OWNERSHIP                       │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│  Infrastructure    Development    Operations    Opportunity      │
│  ────────────────  ────────────   ──────────    ────────────     │
│  • Compute         • Engineering  • Support     • What else      │
│  • Storage         • QA           • Monitoring  • could team     │
│  • Network         • DevOps       • On-call     • be building?   │
│  • Third-party     • Management   • Training                     │
│    APIs/SaaS       • Contractors  • Incidents                    │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘

---

Infrastructure Cost Reference

Cloud Compute Pricing (2024-2025)

AWS EC2 On-Demand (US regions)

| Instance | vCPU | RAM | Monthly Cost | Best For | |----------|------|-----|--------------|----------| | t3.micro | 2 | 1GB | $8 | Dev/test | | t3.medium | 2 | 4GB | $30 | Small apps | | t3.large | 2 | 8GB | $60 | Light production | | m6i.large | 2 | 8GB | $70 | General production | | m6i.xlarge | 4 | 16GB | $140 | Medium workloads | | m6i.2xlarge | 8 | 32GB | $280 | Heavy workloads | | c6i.2xlarge | 8 | 16GB | $250 | CPU-intensive | | r6i.2xlarge | 8 | 64GB | $370 | Memory-intensive |

GPU Instances

| Instance | GPU | VRAM | Monthly Cost | Best For | |----------|-----|------|--------------|----------| | g4dn.xlarge | T4 | 16GB | $380 | Inference | | g5.xlarge | A10G | 24GB | $730 | ML training/inference | | p4d.24xlarge | 8x A100 | 320GB | $23,000 | Large model training |

Savings Options

| Plan | Savings | Commitment | |------|---------|------------| | On-Demand | 0% | None | | Reserved (1yr) | 30-40% | 1 year | | Reserved (3yr) | 50-60% | 3 years | | Spot Instances | 60-90% | Can be interrupted |

Database Pricing

Managed Database (AWS RDS PostgreSQL)

| Instance | vCPU | RAM | Monthly Cost | Connections | |----------|------|-----|--------------|-------------| | db.t3.micro | 2 | 1GB | $15 | 50 | | db.t3.medium | 2 | 4GB | $50 | 100 | | db.m6g.large | 2 | 8GB | $120 | 200 | | db.m6g.xlarge | 4 | 16GB | $240 | 400 | | db.r6g.xlarge | 4 | 32GB | $350 | 500 | | db.r6g.2xlarge | 8 | 64GB | $700 | 1000 |

**Add for storage**: $0.115/GB/month (gp3) **Add for IOPS**: $0.02/IOPS/month (over 3000 baseline)

Redis/ElastiCache

| Node Type | RAM | Monthly Cost | |-----------|-----|--------------| | cache.t3.micro | 0.5GB | $12 | | cache.t3.medium | 3GB | $50 | | cache.m6g.large | 6.4GB | $100 | | cache.r6g.large | 13GB | $175 |

Storage Pricing

| Service | Cost | Use Case | |---------|------|----------| | S3 Standard | $0.023/GB | Frequently accessed | | S3 Infrequent | $0.0125/GB | Backups, archives | | S3 Glacier | $0.004/GB | Long-term archive | | EBS gp3 | $0.08/GB | Block storage | | EBS io2 | $0.125/GB + IOPS | High performance |

Network Costs (Often Overlooked!)

| Traffic Type | Cost | |--------------|------| | Data IN | Free | | Data OUT (first 10TB) | $0.09/GB | | Data OUT (next 40TB) | $0.085/GB | | Inter-AZ transfer | $0.01/GB each way | | Inter-region transfer | $0.02/GB | | CloudFront to internet | $0.085/GB |

---

Development Cost Estimation

Engineering Cost Framework

Development Cost = (Hours × Hourly Rate) × Complexity Factor × Risk Buffer

Hourly Rate (Fully Loaded):
- Junior Engineer: $75-100/hr
- Mid-level Engineer: $100-150/hr
- Senior Engineer: $150-200/hr
- Staff/Principal: $200-300/hr

Complexity Factors:
- Greenfield, known tech: 1.0x
- Existing codebase, known tech: 1.2x
- New technology for team: 1.5x
- Complex integrations: 1.3x
- Regulatory/compliance: 1.4x

Risk Buffer:
- Well-defined requirements: 1.2x
- Ambiguous requirements: 1.5x
- Experimental/R&D: 2.0x

Story Point to Cost Mapping

| Size | Story Points | Hours | Cost (Mid-level) | |------|-------------|-------|------------------| | XS | 1 | 2-4 | $200-400 | | S | 2 | 4-8 | $400-800 | | M | 3 | 8-16 | $800-1,600 | | L | 5 | 16-32 | $1,600-3,200 | | XL | 8 | 32-64 | $3,200-6,400 | | XXL | 13+ | 64+ | $6,400+ |

Team Cost Calculator

## Monthly Team Cost

Engineering Team:
- 2 Senior Engineers × $15,000 = $30,000
- 3 Mid-level Engineers × $10,000 = $30,000
- 1 Engineering Manager × $18,000 = $18,000

Overhead (benefits, tools, etc.): 30%
Monthly Burn: ($78,000) × 1.3 = $101,400

Annual Team Cost: ~$1.2M

---

Build vs. Buy Analysis

Decision Framework

Build vs Buy Decision Matrix:

                    LOW Differentiation    HIGH Differentiation
                   ┌────────────────────┬────────────────────┐
    HIGH Volume/   │                    │                    │
    Usage          │     Consider       │       BUILD        │
                   │      Build         │    (competitive    │
                   │   (cost savings)   │     advantage)     │
                   ├────────────────────┼────────────────────┤
    LOW Volume/    │                    │                    │
    Usage          │       BUY