(Tomb Chamber isn't a spell.)
Tomb Chamber enters the battlefield tapped unless you pay .
, : You may put a land card from your hand onto the battlefield.
: Add or to your mana pool.
Put Tomb Chamber on top of your library: Add to your mana pool.
., 
: You may put a land card from your hand onto the battlefield.: Add 
or 
to your mana pool. to your mana pool. 
