If, like Jamelles find, a card is stored flat in the dark for 20 years, it will receive a high grade
Several factors influence XY card values: card condition (mint cards worth 3-5x more), rarity (holographic and rare cards command higher prices), first edition status, PSA/BGS grading scores, and market demand for specific Pokemon
According to Takahashi, Seto's feelings for Kisara are the basis of Kaiba's modern-day obsession with the "Blue-Eyes White Dragon." After her death, Seto holds Kisara's lifeless body in front of the tablet - notably, this is the vivid vision Kaiba sees during his Duel with Ishizu in Battle City
They're also premium cards in a deck running Transmogrify effects since they let you stow a finisher back into your deck to be tutored up when needed
Pokemon cards can retail for large amounts, but many interested parties remain skeptical