Thanks for your interest.  My current rates are as follows:

Spot art, Black and White:
1/4 page $40
1/2 page $60

Color Work:
1/4 page $80
1/2 page $120

All subject to negotiation at the time of commission. If you are interested in larger pieces, or some other variation, just let me know. Contact me at jcorff @ gmail.com to learn more.