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.
Tap: Add 3 to your mana pool.
Near Mint Condition
A card in Near Mint condition shows minimal to no wear from shuffling or general play. Cards classified as Near Mint/Mint are generally indistinguishable from cards in an unsleeved deck of other Near Mint/Mint cards. Foils in this condition have little or no scuffing or clouding on the front and edges of the card.