So putting someone into debt for years and taking advantage of them can not be concidered immoral?
Well, let me reverse the argument on you. Say that a company can spend a billion dollars and produce treatment X that solves disease Y. We calculate that our stockholders would be happy if the net return is 50M per year over 20 years. That's net, after paying for lawsuits, overhead, costs of production.
And to get the net 50M, we need sales of 250M. There are an estimated 500 customers per year who can pay 500K each for the treatment. They will all go in debt for years to do this.
Should treatment X be produced? Explain what would make the decision moral or immoral.
There may be competitive products produced after this one is out, their product may be duplicated in countries that do not obey our patent law, there may be side products that benefit other diseases, and that the product may be a complete failure.
I believe this is a pretty realistic scenario.
I would like to mention something from a strictly Rand perspective. In the USA today we have here absolutely ridiculous drug prices. Many elderly people are paying $500-1000 per month for drugs that they must have. Rand would note that this is due to the absence of a true competitive market, that it was due to Medicare/Medicaid payments (Government payments) being the primary item determining drug costs instead of the free market. Thus, she would hold the opposite of your position: namely that the presence of partial socialization in the economic system was immoral, and created great hardships for individuals.