Shuffle your library. As many times as you choose, you may exile the top card of your library. If the total mana value of the cards exiled this way is 13 or less, you may cast any number of spells from among those cards without paying their mana costs.
NM-Mint - $1.70
Lightly Played - $1.50
Moderately Played - $1.40
Heavily Played - $1.20
Damaged - $0.90
NM-Mint Non English - $1.70
Lightly Played Non English - $1.50
Moderately Played Non English - $1.40
Heavily Played Non English - $1.20
Damaged Non English - $0.90