A model, not a quote. Change every assumption — engineer cost, build effort, maintenance, horizon and the Enterprise price. Two of the five cannot be built at all, and the model says so rather than inventing a number for them.
Left at zero by default. Fill them only with figures you can defend internally.
Engineer-months are a starting estimate for a production-quality equivalent — not a prototype. Change any of them. Untick a row to model going without it instead of building it.