[kkreamer]

This depends on what you mean by "plain insulin". If you are referring to NPH and R, there's a massive world of difference going to, say, Novolog and Lantus. If you're comparing something like Lantus versus Tresiba, sure, it's more "extended release" Or yes, Afrezza is inhalable. But when people complain about the cost of insulin, they're referring to the cost, and especially the huge cost increases, of insulins like Lantus and Novolog (that have been out for a couple decades now), not the cost of new insulins like Afrezza or Tresiba.