Roamer's Routine is a common Sorcery card from Tarkir: Dragonstorm (TDM), collector number 154. Current market price: $0.18 (foil $0.30), TCGplayer market prices via Scryfall.
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Harmonize {4}{G} (You may cast this card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by {X}, where X is its power. Then exile this spell.)