The free market works great for a lot of things, including Pre-A Porsches. A willing seller, a willing buyer, the price set by the buyer's desire and ability to pay the seller's price, and no need (in this case no ability) for anyone to be able to "make one for less."
It works well because nobody needs a Pre-A Porsche.
With insulin, we have a different situation.
If the "free market" results in a concentration of power on the maker's side (monopoly), the owners can set whatever price they like. Pay it or die.
The "willing buyer" part of the equation goes away. A diabetic cannot wait months or years for some clever Indonesian start-up to fab a factory and begin producing cheap insulin pumps, then arrange a Bitcoin-based gray market distribution system for the US.
It's like this with a lot of medicine and medical care, which is why civilized countries instituted universal medical insurance systems (heavily regulated if not government controlled) decades ago. Every nation which has one—Canada and the UK very much included—has much better health outcomes than we enjoy in the US, and very little (if any) political controversy about it.
I've long been mystified by the inability of market fundamentalists to understand the basics of an asymmetric market.