Cheapest priced copy (Mirrodin): $0.35 at Card Kingdom, near mint, their price list as of .
Mourner's Shield 
Artifact · Uncommon · Mirrodin · #209
Imprint — When this artifact enters, you may exile target card from a graveyard.
{2}, {T}: Prevent all damage that would be dealt this turn by a source of your choice that shares a color with the exiled card.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin | 209 | Uncommon | $0.35 | $0.49 |