Cheapest priced copy (Amonkhet): $0.35 at Card Kingdom, near mint, their price list as of .
Hapatra's Mark 
Instant · Uncommon · Amonkhet · #169
Target creature you control gains hexproof until end of turn. Remove all -1/-1 counters from it. (A creature with hexproof can't be the target of spells or abilities your opponents control.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Amonkhet | 169 | Uncommon | $0.35 | $1.99 |
One ruling from Wizards of the Coast
- 18 April 2017You can target a creature with no -1/-1 counters on it. It will still gain hexproof.