Cheapest priced copy (March of the Machine): $0.59 at Card Kingdom, near mint, their price list as of .
Furnace Reins 
Sorcery · Uncommon · March of the Machine · #141
Gain control of target creature until end of turn. Untap that creature. Until end of turn, it gains haste and "Whenever this creature deals combat damage to a player or battle, create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.59 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| March of the Machine | 141 | Uncommon | $0.59 | $0.79 |