When Phyrexian Devourer's power is 7 or greater, sacrifice it. Exile the top card of your library: Put X +1/+1 counters on Phyrexian Devourer, where X is the exiled card's mana value.
NM-Mint - $30.30
Lightly Played - $28.80
Moderately Played - $27.30
Heavily Played - $24.20
Damaged - $19.70
NM-Mint Non English - $30.30
Lightly Played Non English - $28.80
Moderately Played Non English - $27.30
Heavily Played Non English - $24.20
Damaged Non English - $19.70