Cheapest priced copy (Assassin's Creed): $0.35 at Card Kingdom, near mint, their price list as of .
Hidden Footblade 
Artifact — Equipment · Uncommon · Assassin's Creed · #34
Flash
When this Equipment enters, attach it to target creature you control. That creature gains first strike until end of turn.
Equipped creature gets +1/+0 and has haste.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Assassin's Creed | 34 | Uncommon | $0.35 | $0.49 |
| Assassin's Creed | 216 | Uncommon | — | — |