how to find out the value of my pokemon cards accurately a Pokémon card collection? How do I know how

Format: Commander Estimated Bracket: 3 (1 Game Changer) User Submitted Deck Deck Date: May 25, 2020 Archetype: Yeva, Nature's Herald Loading

Anyway, these are the cards: Dimir Spybug Disinformation Campaign Sinister Sabotage Thoughtbound Phantasm Thought Erasure Unexplained Disappearance Whispering Snitch There could be a world where surveil gets a real set again and these could find their way into Pioneer decks

#5 Team Rockets Mewtwo ex UR (~6,000 / ~$40) The gold-bordered Ultra Rare variant

10: You gain 7 life, draw seven cards, then put up to seven permanent cards from your hand onto the battlefield

This is infuriating