Kels, Fight Fixer One of the simplest payoffs for any archetype is to tack card draw on it somewhere, which allows Kels, Fight Fixer to be a respectable sacrifice commander
Because demand is so high, folks seem willing to pay the marked-up costs
Green, lean, keen, and mean, goblins are a highly cherished creature type in Magic: The Gathering, and there are all sorts of popular MTG goblin decks available in a variety of formats
Better yet, due to how Replicate works (the copies go on the stack individually and resolve individually), counterspells are useless against it
If you have any synergy with this, in the form of restricting resources or flickering Tax Collector, this can be really backbreaking
A Prismatic Evolutions Umbreon ex SIR hiding in a binder of Scarlet & Violet cards could be worth hundreds