Cheapest priced copy (Eldritch Moon): $0.49 at Card Kingdom, near mint, their price list as of .
Cathar's Shield 
Artifact — Equipment · Common · Eldritch Moon · #192
Equipped creature gets +0/+3 and has vigilance.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.49 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Eldritch Moon | 192 | Common | $0.49 | $2.49 |