Steam has currently a sale of various Stardock games.
The “Galactic Civilizations” series has also a standing fan community on CFC, and “Galactic Civilizations III” (Ultimate Edition) is right now discounted from 91€ down to 32€. You can discuss this game here.
The game “Fallen Enchantress” is a turn-based fantasy game, and was co-developed by Kael, who was the lead designer of the Civilization 4 mod “Fall From Heaven 2”. The Ultimate edition is currently discounted from 39€ down to 17€, the legendary edition from 25€ to 10€. You can read more about the game here.
OffWorld Trading company is a real-time strategy game, about trading on a foreign planet. It was designed by Civ4’s lead designer Soren Johnson, and the Ultimate edition currently discounted from 82€ down to 30€. You can discuss this game here.