Cheapest priced copy (Modern Horizons 3): $0.35 at Card Kingdom, near mint, their price list as of .
Inventor's Axe 
Artifact — Equipment · Common · Modern Horizons 3 · #126
Flash
When this Equipment enters, you get {E}{E} (two energy counters).
When this Equipment enters, attach it to target creature you control.
Equipped creature gets +2/+0.
Equip—Pay {E}{E}.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons 3 | 126 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 7 June 2024If the target creature becomes an illegal target, Inventor's Axe remains on the battlefield unattached.
- 7 June 2024Inventor's Axe doesn't enter the battlefield attached to a creature. Instead, Inventor's Axe enters the battlefield and then its triggered ability attaches it to a creature. You may cast Inventor's Axe even if you don't control any creatures.