Champion sale

Now and then we are blessed with a Champion sale - this time we have been given the chance to purchase Gragas, Cassiopeia and Skarner for 50% of their original price (very considerable, seeing as the saving is about 30 games worth of IP for Cassiopeia).
You can check out the post here http://euw.leagueoflegends.com/news/champion-sale-50-skarner-cassiopeia-and-gragas.

Personally, i'm trying out Graves as he's in the free rotation.