Cheapest priced copy (Avacyn Restored): $3.49 at Card Kingdom, near mint, their price list as of .
Druids' Repository 
Enchantment · Rare · Avacyn Restored · #176
Whenever a creature you control attacks, put a charge counter on this enchantment.
Remove a charge counter from this enchantment: Add one mana of any color.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $3.49 to $5.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Avacyn Restored | 176 | Rare | $3.49 | $5.99 |
2 rulings from Wizards of the Coast
- 1 May 2012You can activate the second ability of Druids’ Repository multiple times in the same turn. It’s a mana ability, doesn’t use the stack, and can’t be responded to.
- 1 May 2012The first ability of Druids’ Repository will trigger once for each creature you control that attacks.