When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
NM-Mint - $5.60
Lightly Played - $5.30
Moderately Played - $5.10
Heavily Played - $4.50
Damaged - $3.70
NM-Mint Non English - $5.60
Lightly Played Non English - $5.30
Moderately Played Non English - $5.10
Heavily Played Non English - $4.50
Damaged Non English - $3.70