That we don't know whether software development is subject to economy or diseconomy of scale stuck out to me. Estimation cost (of doing the estimation, not con

That we don't know whether software development is subject to economy or diseconomy of scale stuck out to me. Estimation cost (of doing the estimation, not consequences of estimation) not mentioned. Is estimation itself significantly costly relative to subject of estimation? To the extent open source works relatively well as a development practice, how much of a role does suppression of estimation play (assuming there is suppression; harder to even pretend to hold anyone to an estimate without a contract, so why bother)?