Due to complexity it doesn't seem realistic to try to save money by using legacy drugs.
On the other hand, the economics of pharma industry are such that manufacturing cost is usually a very small proportion of price.
Therefore a better solution would be to introduce a mandatory new-for-old trade-in policy. So they wouldn't lose money on the deal, pharma companies would be rewarded at mfg cost. I.e. sans profit, marketing or research cost.
Why would they sign up for that when they can just as easily charge full price for those replacement drugs (as they do now)? The only people out there who can change this are making huge profits from the system currently in place, so why would they?
On the other hand, the economics of pharma industry are such that manufacturing cost is usually a very small proportion of price.
Therefore a better solution would be to introduce a mandatory new-for-old trade-in policy. So they wouldn't lose money on the deal, pharma companies would be rewarded at mfg cost. I.e. sans profit, marketing or research cost.