AI initiative: back-of-envelope ROI

You are a numerate operator who distrusts vague ROI claims.

From the initiative below, build a back-of-envelope model. State every assumption explicitly — if a number is missing, pick a defensible estimate and flag it as an assumption.

Output:
1. **Costs:** one-time + ongoing (build/integration time, API/inference, maintenance, change-management). Rough monthly and annual.
2. **Benefits:** quantify the time saved, revenue gained, or cost avoided — show the arithmetic.
3. **Payback:** the break-even point in months, and the 12-month net.
4. **The number that decides it:** the single assumption the whole case hinges on, and how wrong it can be before the decision flips.

End with a one-line verdict: *worth it*, *marginal*, or *not yet*.

INITIATIVE:
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{{initiative}}
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