All pre-Mordor Expansions are on sale for 99 points in the in game store. They are Moria, Mirkwood, Isengard, Rohan and Helm's Deep.
THESE ARE THE QUEST PACKS ONLY! Some expansions have the Instance clusters included like Moria and Mirkwood. But for Isengard, Rohan and Helm's Deep if you want the instance clusters for them, it's an additional 99 points.
The sale can be found in the NEW TO THE STORE section.