Cheapest priced copy (Dominaria): $0.59 at Card Kingdom, near mint, their price list as of .
Curator's Ward 
Enchantment — Aura · Uncommon · Dominaria · #49
Enchant permanent
Enchanted permanent has hexproof.
When enchanted permanent leaves the battlefield, if it was historic, draw two cards. (Artifacts, legendaries, and Sagas are historic.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.59 to $4.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dominaria | 49 | Uncommon | $0.59 | $4.49 |
3 rulings from Wizards of the Coast
- 27 April 2018If you give hexproof to an opponent’s permanent, such as by enchanting it with Curator’s Ward, that player can still target that permanent, but you can’t.
- 27 April 2018A card, spell, or permanent is historic if it has the legendary supertype, the artifact card type, or the Saga subtype. Having two of those qualities doesn’t make an object more historic than another or provide an additional bonus—an object either is historic or it isn’t.
- 27 April 2018If Curator’s Ward is attached to a historic permanent you don’t control, you draw two cards when that permanent leaves the battlefield, not that permanent’s controller.