Wait a sec, Gilead made $12.5B in 2015, $4B this year, on a single drug, and that's not enough? Gosh, I remember when $16.5B was a lot of money.
https://en.wikipedia.org/wiki/Cost_of_drug_development
(These costs include the other 90% of drugs that have probably failed at some development stage)
There is also now a $300 generic.