Early last year, a holographic Charizard card from 1999 sold on eBay for $311,800
This has called the canonicity of pre-rev sources into question, but at the time the official stance was that everything still counts, unless a new source directly contradicts it
The stack is first in, last out meaning that when multiple effects are cards are on the stack, the most recent effects and cards resolve first
(Costs 2 Colorless Energy).Flaaffy Lightning CommonHP: 90 Weakness: Unknown Retreat Cost: 1 Colorless Attack: Electric Punch 40 damage (Energy cost unknown).Hydreigon Darkness RareHP: 150 Weakness: Grass Retreat Cost: 2 Colorless Ability: Roar in Unison Attach 2 Darkness Energy from your Energy Zone to this Pokemon
Unlike instants though, they stick around afterwards and provide continuous effects
For example, we know Post Malone is an avid fan of Magic could someone acquire a card signed by him for their collection