It depends almost entirely on whether the specialty position is defensible. A qualified technical-fabrics producer is valued as a specialty manufacturer; a company holding the last share of a declining commodity is valued closer to its assets.
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The practical test buyers apply is whether the customers could switch. If the product is specified into a customer qualification, made on equipment that would be expensive to replicate, or produced to formulations the company owns, the position is defended and it prices accordingly. If the revenue is legacy volume with customers who have been shrinking for a decade, the earnings multiple compresses and the value concentrates in the physical plant: heavy power service, water and effluent capacity, floor loading, and a site that would be difficult to permit today. Both outcomes are worth pursuing deliberately. The mistake is discovering which one you have at the end of a failed sale process rather than at the beginning of a planned one.