Diminishing returns and loot rarity

I played Magic the Gathering for a decade and up to now that is the game I spent the most money on, in the order of $ 10,000 overall, a thousand dollars per year. And I wasn't even playing competitively, my participation in the Pro Tour tournaments was limited to being a judge. But I loved building decks, and the more different cards you had, the more decks you could build. MtG cards come in 15-card boosters, with 11 common cards, 3 uncommon cards, and 1 rare card. But as there are about as ma

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