Ahhh... that also depends. If he is looking for a selling price, that's different than a "value" price.
A particular morph might only sell for $xx, but if it's part of a breeding project that you are really into, then it's worth more than that to you. A female that is a good eater for you might be worth more to you than another similar snake that is more picky. Worth to YOU will always be difficult to quantify for others.
I adore my pied carriers for what they will produce, and it really killed me to sell my visable pied. The selling price was much lower than her worth to me, but I HAD to have funds immediately.
Wolfy