(Grass-Shelter isn't a spell.)
Grass-Shelter enters the battlefield tapped unless you pay 1 life.
, : Look at target player's hand.
: Add or to your mana pool.
Sacrifice Grass-Shelter: Add or to your mana pool.
, 
: Look at target player's hand.: Add 
or 
to your mana pool. or to your mana pool.
