Signed backlog with verifiable margin supports the valuation directly. Quoted pipeline does not count, and backlog priced before a material cost increase can reduce value rather than add to it.
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Buyers evaluate backlog contract by contract, looking at what is signed, what has been billed, what margin remains, and whether the remaining cost estimates are reliable. Where percentage-of-completion accounting is used, the cost-to-complete estimates are effectively part of the earnings, and a quality-of-earnings review tests them. A backlog that has already consumed its contingency, or that was priced when steel was materially cheaper, transfers a loss to the buyer, and they will price it accordingly. The most valuable pre-sale work in fabrication is tightening job costing so that actual hours and actual material land against the job, because that is what makes the margin credible.