I purchased the 2016 OAT Destroyer Supreme with Organic Chemistry Odyssey set, which I found very helpful. I bought them new which cost $300 but I was able to obtain the OAT scores I desired which got me into the school of my choice. I would purchase them again if I were to have to go through the same process of preparing for the OAT. If you are interested I'm selling mine for $200. I worked out sample problems in notebooks so the books are still in great condition.