End price should remove by product prices to have a fair value

[Jonixo]

Crushed rock recipe for an example uses 12 coal to make 2 crushed coal and 1 crushed mixed rock, if coals cost 1$ each calculator will price crushed coal at 6$, but crushed rock also worth same or twice the coal (1$-2$), so realistic price for crushed coal should be 4$-5$.

Maybe this can be done with some kind of check box "subtract by product profits" kinda thing if possible?

[aritchie05]

This is actually manually implemented for Barrels specifically in Oil Drilling. Need to generify it as a feature, allowing users to set a sell price for byproducts and subtract the value of the byproducts from the cost if the feature is enabled.