Advertising...I don't know.
I still think if it costs $1billion to develop and only 1,000,000 people will use that product over the next 5 years that still equates to a 1,000 bucks a head, just for overhead.
If 1,000,000 people use the drug worldwide, but only 100,000 pay the development cost...for those 100,000 the cost will be approximately $10,000 per head.