I agree, I don't think manufactures plan on making batches of 1% or less tolerance passive components, but rather make a large batch run and then measure and sort to the various tolerances offered. This extra sorting labor is what increases the price for the better tolerance components.
I once worked for a mini-computer company that would pay extra for 7400 series ICs that would be guaranteed to work over a larger Vcc range then the standard offering. The manufacture would just test to that higher spec and paint a blue dot on them and ship them off to us.
Lefty