Pokmon card value is determined by: rarity (limited print runs), condition (PSA 10 commands premiums), historical significance (prototypes, trophy cards), iconic status (Charizard, Pikachu), grading (professionally authenticated), and market demand (collector and investor interest)
Well allow ourselves one more really expensive thing, which is Agent of Treachery
But there's so many other good ones too: blow up enchantments/artifacts with Harmonic Sliver, steal stuff with Admiral Beckett Brass, burn creatures with Dragon Tempest, and cast one-sided board wipes with Thundercloud Shaman
It enters with as many counters as you can afford, and from there either bulks up or shares the love by passing counters to the rest of your creatures