Not to be a dick, but here in NADA book for this quarter say's the avg retail for a 2004 GSXR-750k4 is only $6,610. I would MAYBE put an extra 1,000 for the accessories.
At my dealership I wouldnt even market it as high as you have it. Just my .02!
The only people that use KBB are the ones that dont have access to NADA and Black books.