My current fav vendor is gamersgate (primarily because they don't require a storefront client to be running when playing their games, and the game itself is bit-compatible with publisher/developer released patches - so no patch delays like we see on Steam games that aren't published by Valve or using Steamworks DRM).
Any sales forthcoming through gamersgate? Alternately, will DKS be a daily sale through Steam during the holiday sale event, or is the current sale price the only planned sale through Steam during the holiday sale event?