Look up the comp ratios of some of the major investment banks. It can easily be 50%. As with all professional services firms, the biggest costs are people and real estate.
Is that percentage high or low compared to the products of low skilled labor?
I think he's saying the money client pay to investment banks is a small compared to size of the deals bankers advice / underwrite etc.
But it is large compared to what the shareholders earn, and they are the ones ultimately pulling the strings. The days of the white-shoe partnership are long gone...