This is not completely correct. Mirko gave us an idea of the differences in production costs already. With let's say three package sizes instead of only one you will have to stock three items instead of one with every size you make. You definitely would have to take stock- and shortfall costs into consideration in calculating end user prices as Mirko - as being a manufacturer and distributor- has to. It's not guessing but knowledge of merchants practice here. As with Ilford these costs have to be calculated by the distributors though, assuming Ilford - as a mere manufacturer - is not holding stock. As to the amount of these costs it's -you are right here- just guessing.
Originally Posted by mikebarger