Cheapest priced copy (Scars of Mirrodin): $0.35 at Card Kingdom, near mint, their price list as of .
Darksteel Sentinel 
Artifact Creature — Golem · 3/3 · Uncommon · Scars of Mirrodin · #152
Flash (You may cast this spell any time you could cast an instant.)
Vigilance
Indestructible (Damage and effects that say "destroy" don't destroy this creature. If its toughness is 0 or less, it's still put into its owner's graveyard.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Scars of Mirrodin | 152 | Uncommon | $0.35 | $0.99 |