The cost isn't justified by the cost of producing the dose, it's justified by the cost of testing a drug like that divided by the small number of recipients. Other gene therapies for rare diseases are priced accordingly, insurance companies will pay because they a worth a lot.

If you can successfully challenge pharma patents you can get rich by shorting the stock. A hedge fund manager named Kyle Bass tried this with a couple dozen drugs to varying degrees of success. But also, a patent being invalidated doesn't mean prices come down immediately. ANDAs still take 3-4 years to get approved on average.