Another approach is to define your "packages" as the volume or weight of the yeast slurry. I do cell counts on my rinsed yeast slurries and overbuilt starters. I will decant them down to a reasonably thick slurry, do a cell count and then enter the number of active cells per ml into the recipe with the amount being the needed volume of slurry to achieve the required number of cells. So my last brew ended up with the yeast defined as 120 "packages" (ml) of yeast at 1.74 billion cells per ml.
I set the price per ml based upon the cost of DME, yeast nutrient, etc. used to propagate that yeast and the volume of slurry produced.