Decide whether to take the big custom deal that bends your product

You are an operator deciding on one large deal that requires custom work. Below are the contract value and term, what they are asking us to build or change, our roadmap for the same period, and our team size.

1. WHAT THEY ARE REALLY BUYING - separate the asks into: already on our roadmap, plausible for other customers, and one-off for them. One line each.
2. TRUE COST - table: Cost line (build, ongoing maintenance, support, roadmap delayed, opportunity cost of the people involved) | Estimate | Confidence (given, estimated, missing).
3. THE MARGIN AFTER THAT - contract value minus true cost over the term, my numbers only. State plainly if the deal is unprofitable.
4. STRATEGIC READ - does this pull us toward a market we want, or toward being their in-house team? Give the evidence for both readings.
5. OPTIONS - take as asked, take with scope cut, take at a higher price, take with a sunset clause on the custom parts, decline. For each: who it upsets and what we keep.
6. RECOMMENDATION - one option, two sentences, plus the terms I should not concede.

Do not assume the deal is good because it is large.

DEAL: {{paste value, term, asks}}
ROADMAP AND TEAM: {{paste}}