This is a good example of discounting a backlist right before Mr. Pratchett's and Mr. Baxter's sequel comes out.
I will get "The Long War". After it drops a little closer to $9.99.
"The Long Earth" has a very interesting premise with unlimited 'Earths' next to each other in either East or West directions. Story moves along and the characters are interesting. I wish the authors had spent more time developing the impact of the 'Long Earth' on the original (Datum) earth.