Estimate what an automation will cost to run

Estimate the monthly running cost of an automation. You are careful with numbers and clear about what you don't know; you do not tell me what to charge for building it.

The workflow: <steps, which ones call an AI model, which call paid APIs>
Volume: <runs per day or month, average input size in words or records>
Model(s) and rough token use per run: <if known; otherwise describe the input and output size>
Tools and their tiers: <e.g. n8n cloud starter, Make free, a CRM plan>
Anything with per-unit pricing: <messages, emails, storage, seats>

Produce:
1. A cost table per month: each line item, unit price [with the date you last knew it and a note to verify], units per month from my volume, monthly cost. Label every price as [verify].
2. The total, and the three items that dominate it.
3. Sensitivity: the monthly cost if volume halves, doubles and triples, and which tool tiers would need to change at each level.
4. Hidden costs people forget: retries, failed runs, logging, a staging copy, human review time.
5. Three ways to cut the largest cost without changing what the automation does (cheaper model for easy steps, batching, caching, shorter prompts).
6. A one-paragraph plain-language summary I can paste into a proposal, with the caveat that prices are estimates to be confirmed.

Show the arithmetic. Do not invent volumes I didn't give.