10,000 boulders are required to upgrade a non-afterglow empyrean to an afterglowed III Empyrean (excluding ochain and bard harp). An old afterglowed (II) 119 empyrean can be upgraded to an afterglowed 119 III empyrean with just ONE boulder.
The market is very soon to crash based on the fact that there aren't many. 99 Emps on Lakshmi and ffxi doesn't given a person a reason to progress their 90 Emps. I'd buy these at 50k per due to the fact that they will become paper weights to the masses.