Wouldn't that depend on the condition being CURED?
i.e. If a chronic disease costs the patient or health
care system more than $200,000 yearly, how much is a
guaranteed cure worth?
#850K is their opening bid not what they realistically
expect to receive.
If the terms include a guaranteed cure or the drug is free,
then it's simple arithmetic to decide what the price could be.
This is not my area of expertise, just a logical guess at the rationale.