sketch - $5.50. can vary from one detailed sketch to several looser, quicker ones. (examples)
shaded black and white - $10.50-$15.50, depending on background. can be digital or in inks. (example, example, example)
lines w/color - $15.50 full body, $10.50 bust (example)
shaded pic with transparency - $20.50 (example, example)
shaded pic with simple background (meaning: does not take up entire picture, includes some transparency, or most of it is pure color) - $25 (example, example, example)
complete picture (shading, complex bg, etc.) - $35 minimum, may be raised (example, example, example)
custom character design or reference sheet - $30 min