When the next CK2 sale will be?

Its Paradox, so soon.

ok

You should look into trading it, you would pay about the same price as it would be on sale (more or less). I bought the game + a few DLC's for 5 TF2 keys = 9 dollars (something like that). I later bought all of the other dlc's for 15 dollars (separate amazon keys! that trade took over an hour just for the trader to copy all the keys, but it went well!) So in total I paid 24 dollars, which is about 50%- off in dollar price. A little bit more expensive then if everything would be 75% off on sale, but it was worth it for me!