Sheldon Brown and Mike Kone put one together long ago, not a Kelly blue book but a marque pricing guide. A reasonable attempt. The prices are below market today, so that might give some guidance in general. Mike began an update but he set it aside.

The late Dr. George Hollenberg kept complaining about the lack of one. That got no traction that I could tell.

Often some exceptional bikes get overlooked as they are not well known. Which leads me to the comment that brand awareness often means as much or more than absolute quality. In general, that awareness ( with positive press) is money in the bank.