If that is true, then I have to admit you are right. Even that discount I have mentioned 7-11 for vanilla is nothing compared to this. Hopefully more money per each sale goes to developer from GOG. In this case I would not regret paying more.
Edit: could not help and looked at steam now. AoM is -15% from 17.99 to 15.29 Eur. Do we live on the same planet? 