Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.
Near Mint - $275.30
Near Mint Non-English - $275.30
Lightly Played - $247.80
Lightly Played Non-English - $247.80
Played - $192.70
Played Non-English - $192.70
Heavily Played - $165.20
Heavily Played Non-English - $165.20
Damaged - $137.70
Damaged Non-English - $137.70