Presumably partly for this reason, a bunch of "new" drugs are minor modifications to some existing drug to secure a new patent and create a new branded product whose modest advantages over the old drug (if any) are inflated by the marketing machine into being some kind of revolutionary advance.

Does it increase the number, or does it just reallocate customers from one company to another? And I'll repeat my question - how high do drug prices have to get, before further increases can no longer be justified because some scrap of the revenue goes towards R&D?