Now you can get the entire line of Twilight: 2013 products in pdf format for only $10, as a special holiday promotion. That is just incredible, as it includes not only the core rules, but all the sourcebooks, modules, adventures, addenda, etc. Wow!
Here's the description from a reviewer on Drivethrustuff.com:
A complete bundle of nearly everything you would want for the excellent latest version of Twilight 2000. Some parts of the new time line are a little weak because they are too similar to the old cold war time line. The various stages of the rules vary from very easy to lean and start to play to very realistic and robust making them suitable for nearly any gaming group interested in this kind of genre.If you have fond memories like I do of Twilight: 2000, or have heard good things about the third edition and just held off for whatever reason, there's really no excuse now not to take the plunge. Merry Christmas indeed!