Well, it depends on the package. For example, the Super Game Creators Pack includes: DBPro, Texture Maker, 3D Canvas, Cartography Shop, DarkMATTER and 6 months DBDN Membership as seen at the top of this webpage, and there are also other packages, it just depends on which one you bought.
About Darkmatter, same answer, it depends. If you're brilliant at 3D modelling, texture creating and have a large database of sound fx and music, its not worth it, or you might not need any of these. However, if you're a beginner in all of the areas, it might be smart to get it, because you wont be able to do all this after a few tries, but you have to practice a lot to gain each of these skills.
Whatever I did I didn't do it!