(Crater of the Dead isn't a spell.)
Crater of the Dead enters the battlefield tapped unless you pay .
, : Tap target artifact with converted mana cost X or less.
, Pay 1 life: Add or to your mana pool.
, , Sacrifice Crater of the Dead: Draw a card.
.
, 
: Tap target artifact with converted mana cost X or less., Pay 1 life: Add 
or 
to your mana pool.
, , Sacrifice Crater of the Dead: Draw a card.
