King Trode's Alchemy Jar

Sacrifice two artifacts, {t}: Return target artifact
from a graveyard with mana value less than the
combined mana value of the sacrificed artifacts
to the battlefield under your control.

Sacrifice three artifacts, {t}: Search target player's
library for an artifact with mana value less than
the combined mana value of the sacrificed
artifacts and put it onto the battlefield under your
control.