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 - $34.60
Lightly Played - $32.90
Moderately Played - $31.10
Heavily Played - $27.70
Damaged - $22.50
NM-Mint Non English - $34.60
Lightly Played Non English - $32.90
Moderately Played Non English - $31.10
Heavily Played Non English - $27.70
Damaged Non English - $22.50