There are a handful of creatures in Commander that are so good that every deck with their colors is enhanced by running them
Urza, Lord High Artificer isnt a commander that's here to play fair: It's one of the top cEDH commanders (which is even more impressive given the hard time mono-colored commanders have at the highest tier), and it already has another crazily priced printing: Its Mystery Booster 2 version hovers around $380
Id have said 3 mana for an enchantment that draws a card a turn might be a little slow for todays Magic, but given that the Arena is pretty popular on, well, Arena, maybe theres some legs here after all
Triumph of the Hordes and Tainted Strike are also infect cards that often result in one or more players dying from one card, but theyre a little bit off-theme for this list
Theres also a level of provenance to the sale
After a few Jet Punch attacks, you can move Palafin from your Bench to the Active Spot to swing for a mighty 210 damage