In this study, the authors do very extensive research as to the actual costs involved with treating type 2 diabetes. They take into account all of the costs including extended medications, medical and hospital stays, and resulting complications from type 2 diabetes. The study finds that the cost of treating this disease as a nation, are in the billions. It does not speak specifically about treatment of the disease. It focuses mainly on what the costs are and, based on models of other illnesses what the expected future costs will be.
For more information about this study you can check it out here.