This is neither immoral nor is it unreasonable.
That's arguable. There is a lot of truth in what you say, it reminds me of a quote in west wing:
TOBY The pills cost 'em four cents a unit to make.
JOSH You know that's not true. The second pill cost 'em four cents; the first pill cost 'em four hundred million dollars.
But what all that 'rah rah capitalism'/'let's not ignore the cost of invention' argument ignores, is that these medicines can be the difference between someone living and someone dying a needless death. The capitalist interest becomes akin to blackmail, holding the health of a loved one hostage for as much as they can charge.
I think it is a very easy to argue that wanting longer to charge higher prices when people's lives are on the line is immoral.