well lets stay with the reassignment for a moment, lets say i have all white doffs and i want to change into one purple, costs as follows:
white to green:
5 whites + 500 dil = 1 green
green to blue
5 greens + 2500 dill = 1 blue
blue to purple
5 blues + 5000 dill = 1 purple
5x5000 + 5x(2500) + 25x(500) = 50k dil
so one purple BOFF costing now 50k dilithium and 25 white boffs???
This is actually a case of exponential growth. You have to multiply your greens by 25(5/blue) and the whites by another 5 (5 for each of the 25 greens). There is a small arithmetic error as well. So to correct the numbers:
1(5000) + 5(2500) + 25(500) = 30k dil
so one purple BOFF costing now 30k dilithium and 125 white BOffs..