Let's remember that the drug wasn't there before. That's the price the society pays for a dynamic drug market.
No, the epipen was cheaper before Mylan CEO Heather Bresch decided to jack the price to +$600. Of which the company claims to only make $50, a really nice profit for something some people need. That is ignoring the insanity of that $550 overhead. An epipen is a single use stick needle. It delivers a $5 dose of a drug needed to stop anaphylactic shock. Outside the United States these pens are below $10.
You invent something; it's prohibitively expensive for a bit, then the price drops.
Nice theory but reality is different. The dark side to supply and demand is that if you need something, you don't have a choice to buy it. Whatever price I chose to sell it to you is what you have to pay. You want to stay healthy so you need Medicine. Since medicine is something you need, you'll pay whatever price or suffer. If I can make enough profit I can even afford to make sure nobody else competes with me. Either I can create a premium brand like the iPhone or just break the kneecaps of anybody who competes with me like solar roofs versus the local power monopoly.
The best business is to charge people for nothing, like sham medicine. The second best business is to take something that was cheap and already exists then resell it for really high profits.
And because of the first problem the FDA regulate markets like medical products very carefully. You may have to pay more since providing something real is more expensive than just cheating you out of your money. But you shouldn't be getting sham products.
The FDA doesn't regulate the cost to consumers, though. The would require a different, non-existent government organization in the USA. Something like a single payer medicine program.