Whenever Tyrannosaurus Rex attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.
NM-Mint - $18.20
Lightly Played - $17.30
Moderately Played - $16.40
Heavily Played - $14.60
Damaged - $11.90
NM-Mint Non English - $18.20
Lightly Played Non English - $17.30
Moderately Played Non English - $16.40
Heavily Played Non English - $14.60
Damaged Non English - $11.90