Obviously Sanofi should have been able to massively undercut the Mylan price if there truly was xxx% profit margin built in, so it is not really apparent why they didn't do that.
My point about "good guys" was because of the whole tone of the article. A romantic story of two brothers, one of whom became a doctor, and another an engineer, so that they could invent their dream automatic injector. Except that autoinjectors are a 1950s technology, used by most militaries to deliver antidotes to chemical weapons - here's a film from 1963 which demonstrates a device that I have a hard time telling from an EpiPen: https://www.youtube.com/watch?v=oeyW8aoP8mE.
So what the hell was there to even invent, why are these devices covered by any patents at all, why is the FDA allowing just two companies to dominate the market (I am sure plenty of people would like to charge $100 for devices which cost a few dollars to manufacture), and why doesn't a lockstep price hike from $130 to $500 attract the attention of antitrust prosecutors? Because healthcare in the USA is an insane fever swamp...
"In 2013, Sanofi began selling Auvi-Q, which works to quell life-threatening allergic reactions, just as EpiPen does. Sanofi priced Auvi-Q on equal footing with EpiPen. And, initially, Sanofi claims it showed promise of gaining market share and providing real competition to EpiPen, which at the time had more than 99 percent of the market, according to Mylan. But that all changed when Mylan began using dirty tactics, Sanofi alleges."
Looks like Sanofi sold the product to another company - the $4500 number is a price from the company Kaléo.
"In 2015, Sanofi pulled Auvi-Q following quality control issues. The device has since been put back on the market by another pharmaceutical company, Kaléo. The list price of the newly released Auvi-Q is set at $4,500."