[Natsu]

I'd do a multitude of selling it within companies and businesses for their benefits, which won't run cheap.
Then I'd sell it out to people for a very low price so that you can be cured without the hassle of paying hundreds of thousands of dollars.

[VirtusGraphics]

If you make it free, you gain little to continue the work. If you sell it, people may not be able to afford it and therefore it will sell less.
Then I would come to the conclusion that it'd best to sell it cheap, that way a lot of people can buy it, and you earn from it. From there you can invest more money in to other or further research.
I also think it'd be morally acceptable to sell it with low price, because it'd be beneficial to everyone and accesible.