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 - $1,847.50
Near Mint Non-English - $1,847.50
Lightly Played - $1,662.70
Lightly Played Non-English - $1,662.70
Played - $1,293.30
Played Non-English - $1,293.30
Heavily Played - $1,108.50
Heavily Played Non-English - $1,108.50
Damaged - $923.80
Damaged Non-English - $923.80