Inspiring Statuary is a rare Artifact card from The Brothers' War Retro Artifacts (BRR), collector number 22. Current market price: $0.43 (foil $0.97), TCGplayer market prices via Scryfall.
Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)