Here's Justification: Five Views to get you exposed to various views in a nutshell. It includes the New Perspective and others. I think it's a good book to introduce anyone to the different views that exist on this controversial topic (controversial to some). Part of the IVP Pauline Studies Collection
Great bargain, especially since I'm only interested in this particular title.
If you're interested here's the tweet that has the code:
Logos Bible Software @Logos 35m
Twitter #DailyDeal: get 50% off Justification: Five Views with code 32338 at checkout! http://lgs.to/1ipSmFg
DAL