CMC was originally introduced in the Sixth Edition rules change in 1999, one of the biggest rules changes in the games history
This may not seem like it'd see tons of play, but historically, it's been a solid choice for green Pauper decks, especially when faeries became dominant
Lumina, Judgment Dragon, Charge of the Light Brigade, Honest, Solar Recharge, and most of your other core Lightsworn monsters and spells
I don't see a card ever selling for that much
Mewtwo is one of the most featured Legendary Pokmon in the Pokmon TCG , so it's no surprise that it was one of the first immersive art cards in the game
While I can sit down in Rule 0 and mention that I havent got any infinite combos, and that Im not a Voltron damage deck, Im still treated with a sometimes unfair amount of interaction, and thats because Commander players tend to be both empirically led and often emotional