At the end of the day the bottom line is this...............What ever you're selling/trading (Sypder, bike, house, car, atv, snowmobile, etc) its only worth whatever someone will pay you for it.
Look up the value in 4 different books and you'll get 4 different ranges.
Talk trade with 4 different dealers and you'll get 4 different numbers
Have 4 different people reply to your Craig's List ad and you'll get 4 different offers.
The value is entirely market driven. Sometimes the market is in your favor and sometimes its not. For me it seems most of the time its not.
When I purchased my new 2012 RS I did a lot of used Spyder shopping. What I found was I could buy a brand new bike with a better warranty for about the same money as what people were trying to sell their 09 and 10's for. They would all say, "it books for" or "but I have $2500 worth of accessories" or ................. Doesn't matter. The market said I could buy a brand new bike cheaper therefore your bike isn't worth what you're asking. It's really that simple.