Trading Post

Four engines stapled to one rock, each costing one mana and a tap, each gated to a single use per turn. That tap restriction does all the rationing: Trading Post wants to do everything, but it can only do one thing per turn cycle, so the card forces a choice every upkeep about which resource you are short on. The four modes form a closed loop with no leak: discard a card for life, pay life for a body, sacrifice the body to recur an artifact, sacrifice an artifact to draw. Run them in sequence and the only thing you have permanently spent is mana and turns, which is exactly what makes it a fixture in the artifact-grindy decks that want to bury an opponent under inevitability rather than tempo. The Goat token is the quiet hinge: it manufactures both the creature the third mode needs to sacrifice and the chump blocker that buys the time to keep tapping. None of the four rates is impressive on its own (four life, a 0/1, a single card), but the point was never any single line. It was a turn-by-turn valve that converts whichever resource you have a surplus of into whichever one you lack, and it has stayed relevant precisely because that kind of fungible, slow-drip advantage does not rotate out of fashion the way raw stats do.