As far as what to do with your forecast, that is another question altogether. I assume you want to do some sort of optimization. And there are multitudes of different objective functions with constraints. This would really require a closer look at the problem. Please email me directly should you like some assistance with this.
You may not want to model it per se, but instead find out what the cost of the current problem are now and then that's considered the price of the solution.
So if your new drug treats Problem A, and the estimated costs of currently treating Problem A over time is X then the price of the drug could be at least X. There may be arguments that if the drug is beneficial and stops the spread then the price can be X+premium.
If the drug is in an established market with competitors then the drug should be in the same price range to be competitive.