GD&T
Geometric dimensioning and tolerancing, the print language controlling form, orientation and position, and a direct driver of fixturing and inspection cost.
In a quoting argument GD&T is money wearing symbols. A true position callout at a tight diameter does more than constrain the feature. It commits you to a datum scheme, which commits you to how the part is fixtured, which decides whether an existing setup works or a new fixture gets built, and it commits you to proving the callout, which is CMM time on every lot or a gauge somebody has to design and buy. None of that appears as a dimension, and all of it appears as cost.
The estimator’s question is never whether the symbols are legitimate. It is which callouts drive the process and which are decoration. A profile tolerance that the machining process holds naturally costs nothing extra. The same callout tightened one grade past what the process holds moves the operation to a more expensive work center, or adds an operation, and the price moves in steps rather than smoothly. Reading a print well means finding the 2 or 3 callouts that sit near a process boundary, because those are where the quote can be honestly sharpened or honestly defended.
Where it costs money is the callout nobody priced. A datum structure that forces an extra chucking, a flatness spec that means lapping, a position tolerance that turns sampling into 100 percent inspection. These get found at first article if you are lucky and in the field if you are not, and either way the price was fixed months earlier. The takeoff discipline in how to quote a machined part exists largely to catch exactly this class of feature before the number goes out.