* You need to fix a price which would cover the cost of your research that went in (and also for unsuccessful researches that you write off for other ailments) * You have idea about the scale of the ailment but little idea about market acceptance and reaction to your price. * After market has accepted a price, even if it exceeds your predicted consumption by many fold, you have little incentive to change the price especially if insurance is paying for it. * In a new market, because you have already recovered what went in to build the medicine, you can price it better.
In fact, insurance itself work very differently in US vs India. In India, in most cases your insurance won't pay for your medicines and medical expenses (diagnostics) if you don't end up hospitalized for at least a day. And that can govern how medicines are priced here because price has a direct implication on adoption.