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 - $91.40
Lightly Played - $82.30
Played - $64.00
Heavily Played - $54.90
Damaged - $45.70
Near Mint Non-English - $91.40
Lightly Played Non-English - $82.30
Played Non-English - $64.00
Heavily Played Non-English - $54.90
Damaged Non-English - $45.70