you can wait for a long time for -66% at paradox sales. it took more than a year before Horse Lords dropped to -66%. In comparison, Age of charlemagne for Attila reached this after 6 months. the reaper's due, 9 months old has only dropped to -33%. Sure, you can wait, a
lot of us like to have the feeling to play the complete game, like the devs intended
And offcours the issue is with paradox that they "patch" the game so it suits the new dlc.
If you dont have it, you're outta luck. that explains partly why people keep buying them. If you wait for i to go on sale, you're two dlc behind all the time