Warlock : Master of the Arcane is also very good, if a bit old by now. Getting it, Europa Universalis IV AND Age of Wonders III for only $1 is a ridiculous deal.
Plus, like you said, the $12 tier is great for Battletech and Tyranny, plus Stellaris which you get as well since it’s in the BTA tier. If you don’t own any of those 3 games, $4 each for them is a steal.
Sadly, the only game I don’t already own in the whole bundle is Imperator :Rome (the sole game in the $17 tier), and while I’d be happy to add that to my collection, it’s been on sale for as little as $10 in the past. I can wait.