Primal Might's easy to understand, sufficiently powerful, and has a Dinosaur in the art
What makes Arceus VSTAR amazing isnt just its celestial artwork (though, come on, its frame-worthy ), its the total package: mythical status, top-tier playability, and a card that feels important the moment you see it
Value is nice and important and all but most of the relevant portion of the game of magic is fought when both players have cards to choose from and mana is the limiting factor
Frodo, Adventurous Hobbit, Mentor of the Meek, Lobelia, Defender of Bag End, Savvy Hunter, The Gaffer, Night's Whisper, Harmonize, Trading Post, Well of Lost Dreams, Dawn of Hope 10 card draw
At least you can play this in goblin EDH decks
All of this is enough to see collectors clamouring, and the market giving it its worth