This may be common knowledge, but it was new to me, so figured I'd give a heads up to others who may not know:
Always check if the game you want is in a bundle before buying it as you'll get it cheaper if you already have the other games in that bundle.
I went to the Civilization franchise page and figured I'd pick up Civ VI - thankfully I didn't just pick it up there at the 40% but clicked through to the store page for that game and there saw that it was in a bundle with XCOM 2. Since I've already got X2, I just had to pay for Civ VI , and still got the 25% additional bundle discount on top of the 40% for that.
Took me a while to figure out what was going on with that price