Manifest the top card of your library, then put X +1/+1 counters on it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Near Mint - $2.50
Lightly Played - $2.50
Moderately Played - $2.00
Heavily Played - $1.75
Damaged - $1.25
Near Mint Non-English - $2.50
Lightly Played Non-English - $2.50
Moderately Played Non-English - $2.00
Heavily Played Non-English - $1.75
Damaged Non-English - $1.25