Let's go with green
Track Pokmon, Magic & Yu-Gi-Oh market prices by condition, with weekly movement
No need for it to make an emergency exist
Your sheet should include received date, supplier product ID and SKU, purchase currency, invoice cost, allocated freight, destination charges, card name, set code, card number, rarity, illustrator when relevant, quantity, condition tier, storage location, intended channel, list date, sale date, gross proceeds, fees, returns, and net proceeds
It makes for a faster game, but not always the fairest
And, while Amazon might rank pretty low on the places youd probably want to buy your cards from, a 23% discount off the list price of a Collector Booster Box is a solid discount for Avatar: The Last Airbender