Jon Fabeck let me know that Amazon is having a buy two games get one free deal and both versions of Silent Hill Downpour and the Xbox version the HD Collection is part of the promotion!

http://www.amazon.com/gp/feature.html/?ie=UTF8&plgroup=1&tag=34a6-20&linkCode=ur2&docId=1000789521&camp=1789&creative=390957

Source (Amazon) Thanks Jon!