Cost Analysis

Cost Structure

• Do you have current pricing for each option? If not, what's the budget constraint?
• Are there fixed costs (setup, licensing, infra) in addition to variable/usage costs?
• What's the approximate cost at low, medium, and high volume for each option?

Quality and Risk

• Are there latency, reliability, or quality differences between options?
• What's the switching cost if the chosen option doesn't work out?
• Are there compliance, data residency, or vendor lock-in concerns?

Operational Burden

• What does each option require to maintain? (engineering time, ops overhead)
• Is the team equipped to operate the self-hosted or built option?

Strategic Fit

• Is this a core competency to invest in, or commodity infrastructure to buy?
• Does any option create strategic advantage or meaningful dependency?

Phase 3: Gate

When dimensions are covered, stop and ask:

"I have enough to produce the recommendation. Anything to add before I write it up?"

Phase 4: Recommendation Output

Produce the following structured recommendation:

Cost Analysis: [Descriptive Title]

Date: [current UTC date, YYYY-MM-DD]

Context

What decision is being made and why? Include relevant constraints and what triggered this analysis.

Options Evaluated

Cost Comparison

Flag all assumed figures with [Assumed — verify]

Tradeoff Summary

Recommendation

State the recommended option clearly. Include:

• Which option and why
• The volume or condition at which the recommendation changes (crossover point)
• Any conditions that must be met for the recommendation to hold

Risks and Assumptions

List key assumptions and what changes if they're wrong.

Open Questions

Unresolved items that could change the recommendation. Include owner and target date if known.

File Output

Save to:

product-documentation/architecture/YYYYMMDDTHHMMSSZ-cost-<short-description>.md

Example: product-documentation/architecture/20260226T143000Z-cost-gemini-tts-vs-self-hosted.md

Phase 5: Next Steps

After saving, ask: "What would you like to do next?"

Suggest relevant steps based on the recommendation:

• If the recommended option is an API and detailed cost modeling is needed → /ba/api-cost-model
• If the decision affects infrastructure → /architect/infra-design
• If the decision is significant enough to formalize as an architecture decision record → /architect/be-design or /architect/infra-design