There were a large number of games of various genres that had been on sale for Christmas, from at least 3 sellers: Steam, GOG, and Matrix. Some sales were as much as 80% off, while others were lukewarm with 10% off, Still, I managed to find some great OC games for a very decent price. What normally would have cost $107.00, I bought for $35.00. All from the same source, GOG. I did purchase a couple of games from Steam and one game from Matrix, but the savings were not as awesome as I managed on GOG.
Christmas time of the year is usually the best time to get that game (or games) you've been wanting all year long, as the prices, in some instances, really get deeply discounted. If you didn't catch the game sales this year, there is always next year. Happy Gaming!