Use TCGTrends to search for potential buys based on card value changes over time
Before we unveil our top pick, here are a few honorable mentions: 1st Edition Lugia Shining series Tropical Mega Battle Trophy #1: 1st Edition Charizard Forget Wall Street, put your money into Charizards
and some remained in a box for years in one managers office
The skill level here is very minimal, and can help you get rid of cards that you may no longer play with or just lost interest in the hobby
Here are a few more guidelines to use as a starting point: For a 40-card deck, if you really want to have a land that produces a certain color of mana in your opening hand, you should play at least ten lands that produce that color (eleven or twelve to be safe)
It's not often I kill a mechanic in design for being too powerful, but these cards definitely got that honor