I know I've plugged this game before, but this is the cheapest it's ever been.
King Arthur is on Steam for $3, and the Saxons expansion is $1.50, which includes the two other DLCs (which are still $2 each...wat?). Anyway, the whole thing is just $12, and considering $10 of that is the Druids expansion (which just came out today so its not on sale), that's pretty good. I'm not big on strategy games, but I've been having fun with this one.
Linky.
*EDIT: If anyone picks it up and wants to try the multiplayer, hit me up. I haven't tried it yet.