Whir of Invention 49 (The List Reprints)

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.) Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

NM - $10.80
LP - $8.60
MP - $6.50
HP - $4.30
DMG - $2.20