Never done that. Could be useful on resale- that way you have a definite number and value, not something from out your ass.
With the things actually on the bike, I'm still below list for a 650R- even an '07. Once I get the two big ticket items on, then it will be close to the price of an '09. Still under the cost (list + fees + taxes, tags, and registration) for three years ago. I'd say that's pretty damn good. If I were to sell it- not happening- the miles I've put on would negate the value of any modifications anyway