Strategy & Tactics: Dark Ages (thread here) is on sale on Steam for 40% off ($9). However, if that’s still too much, you can buy the bundle that includes it and three other games you’ll never play for $7.64. If it’s too little, you can spend an extra 70 cents and get this other bundle which includes it and another game (which is actually 3 games bundled itself), plus 2 DLC.
Steam bundles! They make no sense, but we love them! Or hate them. Whatever.