brain transplantations prices

A client of a hospital where they made brain transplantations asked about the prices.
The doctor said, ‘Well, this Ph.D. brain costs $10,000.
This brain belonged to a NASA top scientist and costs $15,000.
Here we have a policeman’s brain as well. It costs $50,000.’
The client asked, ‘What? How’s that possible?’
The doctor replied, ‘You see, it’s totally unused.’