Cheapest priced copy (The List): $27.99 at Card Kingdom, near mint, their price list as of .
Doubling Cube 
Artifact · Rare · Fifth Dawn · #116
{3}, {T}: Double the amount of each type of unspent mana you have.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $27.99 to $59.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tenth Edition | 321 | Rare | $32.99 | $59.99 |
| Fifth Dawn | 116 | Rare | $32.99 | $49.99 |
| The List | 10E-321 | Rare | $27.99 | — |
3 rulings from Wizards of the Coast
- 1 December 2004Doubling Cube's ability is a mana ability.
- 1 December 2004Any restrictions on the unspent mana aren't copied. For example, if you have {C}{W}{W}{B} with no restrictions on it and {U}{U}{U} that can be used only to cast artifact spells, you'll end up with {C}{C}{W}{W}{W}{W}{B}{B}, {U}{U}{U} that can be used only to cast artifact spells, and {U}{U}{U} that can be used for anything.
- 1 December 2004The "type" of mana is its color, or lack thereof (if the mana is colorless).