The nice thing about pharmaceutical patents is that they DO expire in 12 years, and then the market can be flooded with cheaper generics, at about a 30% to 80% reduction in cost to the patient.
That's *kind of * true... but not really.
In reality, when a patent is up for expiry, the pharmaceutical companies run out, do some quack study, add some kind of condition that the medication can be used for, then get their patents extended. It's no different than how the MAFIAA continually demand that copyright expiry be lengthened continually.
So, while in "theory" pharma patents may only last 12 years, the reality is that they get extended and the prices stay high.
i.e. You're only going to get low prices on these drugs if you are a very, very, very patient patient.