Though inexpensive, they provide great first-level protection against scratches, dust, fingerprints, and minor bends
Holographic cards, alternate arts, and vintage cards from early sets typically hold higher value
Most Expensive Cards: Collectors Edition and International Edition Collectors Edition and International Edition Its not a secret that the Collectors and International Editions are famous for their cheap Power Nine cards
(Not every card in Battle Partners will be a "Trainer's Pokmon" card.) Info/images from Bulbapedia and PokeBeach
Now these formats, often encourage having a bunch of dudes in play, waiting to draw your enabler, or waiting till turn 4-5 to drop your lord, people will sit on their boardstate and a lot of these decks don't feel like they are encouraging you to stock up on Jace's Ingenuity to refill your hands