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}.
NM-Mint - $40.70
Lightly Played - $36.70
Moderately Played - $32.60
Heavily Played - $28.50
Damaged - $20.40
NM-Mint Non English - $40.70
Lightly Played Non English - $36.70
Moderately Played Non English - $32.60
Heavily Played Non English - $28.50
Damaged Non English - $20.40