Badlands ($400) - This is a dual land card representing swamps and mountains (so it affects spells in both mana pools)
So if a favourite, but expensive, card is in a set that is unlikely to see a remaster, then you have hope it sides into a different one
When synthesizing this list, I was looking at cards that are asymmetrical in their effect, hard to interact with, or have little ways to remove or stop them
Slime Titan full-art playmat
Maybe it was the introduction of Meren of Clan Nel Toth and later reanimation commanders that bumped it off the radar, but I was never really in tune with calling Karador a good Abzan commander
Hybrid as a disguise cost takes this one step further by allowing you to turn the card face up with just one color