Cheapest priced copy (Mirrodin): $0.79 at Card Kingdom, near mint, their price list as of .
Culling Scales 
Artifact · Rare · Mirrodin · #160
At the beginning of your upkeep, destroy target nonland permanent with the lowest mana value. (If two or more permanents are tied for lowest, target any one of them.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.79 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin | 160 | Rare | $0.79 | $1.49 |
4 rulings from Wizards of the Coast
- 1 December 2004Most tokens have a mana value of 0. A token that's a copy of another permanent or card has a mana value equal to that permanent or card's mana value.
- 1 December 2004If the targeted permanent doesn't have the lowest mana value when the ability resolves, the ability doesn't resolve and the permanent isn't destroyed.
- 1 December 2004If the lowest mana value is 3, Culling Scales can destroy itself.
- 1 December 2004You choose the target. If there's more than one nonland permanent tied for lowest mana value, you choose which one to target.