Memorial Vault is a rare Artifact card from Edge of Eternities Promos (PEOE), collector number 145p. Current market price: $0.24 (foil $0.43), TCGplayer market prices via Scryfall.
{T}, Sacrifice another artifact: Exile the top X cards of your library, where X is one plus the mana value of the sacrificed artifact. You may play those cards this turn.