Just out of curiosity, at what point would the cost of the drug not met your definition of fair?
It does seem like they got a great deal.
If their earnings within 2-3 years exceeded double what they paid for the drug, I consider this unfair pricing without much further thought. (Edit) After the correction from the other commenter, it looks closer to an 87% margin. So probably they should've paid more for the company to justify charging that much.