A Base Set Charizard might go for around $60 for a damaged card, one that might have heavy scratches, water damage, or even a crease in the card
Adeline, Resplendent Cathar makes up to three 1/1s every attack, which adds up quickly
Its goaded for the rest of the game and, very importantly, gains the ability cant be sacrificed. Because the ability is targeted, we cant give creatures to a player who has hexproof, like with Leyline of Sanctity or Spirit of the Hearth
(For example, you take your beginning phase as the active player, then the next player in turn order becomes the active player and takes their beginning phase After each player had a beginning phase, do the same for first main, combat phase, second main, ending phase, and then beginning phase again If this creature leaves the battlefield, the active player continues their turn as normal.)
With the right setup, it can even go infinite
Collectors of Magic The Gathering cards value these ratings, as it proves the card is legitimate, and so you'll likely get a higher price for your card than if you tried to sell one without it