Cheapest priced copy (Ice Age): $1.29 at Card Kingdom, near mint, their price list as of .
Ice Cauldron 
Artifact · Rare · Ice Age · #321
{X}, {T}: You may exile a nonland card from your hand. You may cast that card for as long as it remains exiled. Put a charge counter on this artifact and note the type and amount of mana spent to pay this activation cost. Activate only if there are no charge counters on this artifact.
{T}, Remove a charge counter from this artifact: Add this artifact's last noted type and amount of mana. Spend this mana only to cast the last card exiled with this artifact.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $1.29 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ice Age | 321 | Rare | $1.29 | — |
14 rulings from Wizards of the Coast
- 4 October 2004Tapping the Cauldron for the mana is a mana ability.
- 4 October 2004If multiple cards are exiled by the Cauldron, any one of them can be cast.
- 4 October 2004Cards which are not actually in your hand can't be exiled by the Ice Cauldron.
- 4 October 2004You can only cast the spell when you could legally cast it normally. So no casting a sorcery on your opponent's turn.
- 4 October 2004It is possible to have more than one card exiled by the Cauldron. You can tap the Cauldron to remove the charge counter and whatever mana is on it but leave the card there. Later, you can tap it and put in mana and a charge counter to add another card.
- 4 October 2004The mana put in the Cauldron can only be used to cast the given spell, but you can add additional mana to a spell. This means you can pay part of the cost on one turn and the rest of it on the next turn.
- 4 October 2004If the ability to exile a card with the Cauldron is countered, you do not lose the card since it is exiled during resolution.
- 4 October 2004The mana can be used to pay for additional costs to cast the spell.
- 4 October 2004The Cauldron counts only mana spent on it. It doesn't see the value of X, so isn't affected by cost reductions. Thus, if you spent {C}{C}{R}{R} on X, you get {C}{C}{R}{R} later even if X was 6.
- 4 October 2004You do not have to use any mana from the Cauldron when casting the spell if you don't want to. You don't even have to tap the Cauldron and draw the mana, you can just cast the spell using mana from somewhere else.
- 4 October 2004If the Cauldron leaves the battlefield, you can still cast any cards it exiled as though they were in your hand. You just no longer have access to the mana you charged the Cauldron with.
- 4 October 2004Produces mana of the last type used to put a counter on itself, not via any other charge counters.
- 4 October 2004X can be zero. This places a zero mana counter on the Cauldron.
- 4 October 2004If multiple cards are exiled by the Cauldron, the mana can only be used for the card that was exiled by the Cauldron when the most recent charge counter was put there.