Commander creatures you own have "Whenever an artifact or creature you control is put into a graveyard from the battlefield, each opponent loses 1 life."
You give your clients what they want at a fair price. What happens after that is none of your concern.
NM-Mint - $0.50
Lightly Played - $0.45
Moderately Played - $0.40
Heavily Played - $0.35
Damaged - $0.25
NM-Mint Non English - $0.50
Lightly Played Non English - $0.45
Moderately Played Non English - $0.40
Heavily Played Non English - $0.35
Damaged Non English - $0.25
Foil Prices
NM-Mint Foil - $6.10
Lightly Played Foil - $5.50
Moderately Played Foil - $4.90
Heavily Played Foil - $4.30
Damaged Foil - $3.10
NM-Mint Foil Non English - $6.10
Lightly Played Foil Non English - $5.50
Moderately Played Foil Non English - $4.90
Heavily Played Foil Non English - $4.30
Damaged Foil Non English - $3.10