DarkoD13: Yep, probably a pricing error.
Jeets2: Thank you for posting, either the game is really bad or its indeed a price glitch :).
The game is pretty decent. AI is crappy as usual, but it's a nice fantasy 4x with a strong focus on world map tactical combat. It takes some inspiration from Master of Magic, some from Civilization V, and adds some other ideas (like battling across distant planes, i.e. having several different maps in the same game).
It must be a misprice. The game hasn't been even on a 20% discount yet, much less 90%. And _if_ they wanted to increase the player base with a huge discount, they would do that with the regular edition (hoping to sell people the upgrade to the Great Mage Edition later). The current discount only affects the Great Mage edition though, none of the other two editions is discounted.