Daraprim is out of patent. He didn't buy a monopoly right, he just bought a drug that nobody else thought was worth making.
Anyway, the distinction between inventing the drug and buying the patent is an artificial one. If you're going to allow creating monopoly rights--and that you can debate--then making the rights tradable will make the market more efficient.
With drugs in particular, acquisition of promising drug candidates is a major input to the pipeline at the big drug companies. It enables separation of concerns: small startups to develop the drugs and big experienced companies to bring them to market. Creating an artificial distinction between inventors and acquirers precludes that efficient division of labor.
Anyway, the distinction between inventing the drug and buying the patent is an artificial one. If you're going to allow creating monopoly rights--and that you can debate--then making the rights tradable will make the market more efficient.
With drugs in particular, acquisition of promising drug candidates is a major input to the pipeline at the big drug companies. It enables separation of concerns: small startups to develop the drugs and big experienced companies to bring them to market. Creating an artificial distinction between inventors and acquirers precludes that efficient division of labor.