Friend, I am not certain that there really exists any such thing as an "easy cost" justification. I think if you want easy then its as easy as calculating equipment efficiency: Gather the data of what you are putting in and of what your getting out of it and then see if your %Eff is what you want or where you need to add, cut or otherwise. However, I think this site might be able to give you some examples which you might be able to review and then make some decisions:
