You can tell if Pokmon cards are worth individual listings by checking rarity symbols, condition, set, and edition marks, then comparing against recent sold listings on eBay or TCGPlayer market prices
Oh yeah, it also doesn't really care about our endless creature removal, instead using spells to win the game, which means it's a deck we really don't want to face
You can build some decks, try out what you like best and play some games before you spend any money
Heidegger, Shinra Executive* Hasbro executives werent able to swoop in and make Heideggar a stronger card, as hes a mediocre Soldier typal card, mediocre control card, and a mediocre board catchup card