I disagree strongly with that, raising the price of a drug beyond the point of being able to sustain production of it is an ethical minefield, you are disqualifying some patients access to the drug by doing so and you're increasing the burden on patients that can afford the increased price. In our modern world we're pretty happy to excuse moves like this as "market effects" and ignore the real cost of them but there absolutely is a real cost in terms of the quality of lives other human beings are able to lead.