Trading Post is a rare Artifact card from Magic 2013 (M13), collector number 220. Current market price: $0.35 (foil $2.18), TCGplayer market prices via Scryfall.
{1}, {T}, Discard a card: You gain 4 life. {1}, {T}, Pay 1 life: Create a 0/1 white Goat creature token. {1}, {T}, Sacrifice a creature: Return target artifact card from your graveyard to your hand. {1}, {T}, Sacrifice an artifact: Draw a card.