Like most Magic: The Gathering cards, the value of Earthrumbler depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Aetherdrift)
until Felidar Guardian came along.That was enough to break Standard for a time
As expected, some cards stand above others for a variety of reasons, and doing your homework will go a long way in any market
While Sheoldred, Whispering One can be imposing to have out, it doesnt activate that often and is expensive for a commander
GB decks tend to skirt the line between fair and unfair strategies, so these colors tend to be very midrange
Unlike in most other MTG formats, Commander decks require you to have exactly 100 cards