The key here is that most of these cards are simple reprints with new art, while some are brand new cards with a rather limited supply
Ho-Oh ex carries legitimate competitive weight with its Rainbow Wing attack, and the Johto nostalgia factor drives consistent collector demand
But many other artists will command a premium, and sometimes even a large premium, such as artists who are no longer with us (Chris Rush, Glen Angus, for example), or who no longer sign (Chippy, Mike Raabe)
A Vault of Pokmon History : From a high-grade 1st Edition card to a PSA 10 masterpiece, your pack is a golden ticket to Pokmon's elite tier
And since elf decks are packed with cheap mana-producers, your board fills out quickly, meaning that game-ending drain can come online sooner than your opponents expect
I can also see when comparing this data to the raw card value data that I need to hit at least a 9 in order to make the grading process worth it or I would be better off selling the card raw