I guess if a single cavity mold costs $30,000 and a 16 cavity mold costs $110,000 you have an additional expense of ~$80,000, divided over half million parts is 16 cents. So lets say somewhere from 5-10cents per part to go 16x faster. My numbers might be off a bit but seems in the ballpark. I also don't know much a lego brick costs to make in terms of materials/opex.