Like most Magic: The Gathering cards, the value of Morph depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Dragons of Tarkir Tokens)
1st Edition copies are highly sought after, commanding premiums that reflect both the Mewtwo name's enduring market power and the historical significance of this specific card as the canonical representation of Mewtwo's relationship with Team Rocket
Sometimes (particularly for base set cards), people will stamp a card with their own 1st edition stamp
Because so few perfect copies of these common cards exist, getting one graded creates a massive premium
Well start with the best starting hands and strategies
Along the way, this has also meant many seriously creepy art pieces over the years