Cheapest priced copy (Tenth Edition): $0.35 at Card Kingdom, near mint, their price list as of .
Steadfast Guard 
Creature — Human Rebel · 2/2 · Common · Mercadian Masques · #50
Vigilance (Attacking doesn't cause this creature to tap.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tenth Edition | 48 | Common | $0.35 | — |
| Tenth Edition | 48★ | Common | — | $0.49 |
| Mercadian Masques | 50 | Common | $0.35 | $0.49 |