Nothing here is buying advice
The card-collecting site Cardboard Connection suggests eBay as your first step, particularly under sold items, as it will tell you how much your cards are worth without having to spend any money (there are also price guide services that are useful)
C Common Offering to the Immortals X TRAP When your opponent's monster declares a direct attack while you have 3000 or less LP: Negate the attack, and if you do, Special Summon 2 "Ceremonial Tokens" (Rock/EARTH/Level 1/ATK 0/DEF 0), and if you do that, add 1 "Earthbound Immortal" card from your Deck to your hand
Favorite Fallout song: "Pistol Packin' Mama" by Bing Crosby and The Andrew Sisters
It reveals a Number XYZ monster from the Extra Deck with a value between 101 and 107, then you add a monster to your hand with the same type, or the same attribute, as the revealed card
Iconic Pokmon like Charizard, Blastoise, and Pikachu are perennial favorites, and their cards almost always command high prices