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 - $14.70
Lightly Played - $14.00
Moderately Played - $13.30
Heavily Played - $11.80
Damaged - $9.60
NM-Mint Non English - $14.70
Lightly Played Non English - $14.00
Moderately Played Non English - $13.30
Heavily Played Non English - $11.80
Damaged Non English - $9.60