The best thing to do is to compare yours with ads for similar machines in your area. The bluebook value may indicate one thing, but unfortunately, people are hard up right now and are willing to part with things for much cheaper that they should because they need $$$ now. This, unfortunately lowers the value of everything. There will be alot of people trying to lowball you because some kid down the road has the same thing only for $500-$1000 cheaper, but it is probably not as nice as yours. If you hold out for the discerning consumer that recognizes the value of a machine that has been mainained and taken car of, you will get a better price.
Yours truly, sincerelly, love always, Josh aka The DirtDemon.