Digital portrait - 20$ (+20$ for extra character)
Realistic digital portrait - 25$ (humans only)
Examples: http://www.furaffinity.net/view/22695158/
http://www.furaffinity.net/view/24296777/

Halfbody 30$ (+30$ for extra character)
Example: http://www.furaffinity.net/view/22695552/

Fullbody - 40$ (+35$ for extra character)
Example: http://www.furaffinity.net/view/22694923/

Illustration - 100$ or 1 character (background included in the price) (+50$ for extra character)
Example: http://www.furaffinity.net/view/25375978/

Reference - 40-80$ (two views, flat colors, details)
Example: http://www.furaffinity.net/view/23239163/

All examples in my gallery! Please check it =)