Azorius Tinker

Artifice {2}(Whenever this permanent enters the battlefield, you may exile target artifact you control
with a mana cost {2} or less, and return it to play
under its owner's control.)
Flash
{t}: Add {1}. If this mana is not used to cast a
spell with Enchant, Abjure or Artifice, sacrifice Azorius Tinker.