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 - $3,149.75
Near Mint Non-English - $3,149.75
Lightly Played - $2,992.25
Lightly Played Non-English - $2,992.25
Moderately Played - $2,519.75
Moderately Played Non-English - $2,519.75
Heavily Played - $1,890.00
Heavily Played Non-English - $1,890.00
Damaged - $1,575.00
Damaged Non-English - $1,575.00