Brain transplantantion

In the hospital the relatives gathered in the waiting room where their family member lay gravely ill. Finally, the doctor came in looking tired and somber. "I'm afraid I'm the bearer of bad news," he said as he surveyed the worried faces. "The only hope left for your loved one at this time is a brain transplant. It's an experimental procedure, semi-risky and you will have to pay for the brain yourselves."
The family members sat silent as they absorbed the news. After a great length of time, someone sked,"Well, how much does a brain cost?"
The doctor quickly responded, "$5,000 for a male brain, and $200 for a female brain."
The moment turned awkward. Men in the room tried not to smile, avoiding eye contact with the women, but some actually smirked. A man, unable to control his curiosity, blurted out the question everyone wanted to ask.
"Why is the male brain so much more?"
The doctor smiled at the childish innocence and so to the entire group said,"It's just standard pricing procedure. We have to mark down the price of the female brains, because they've actually been used."