I always refer to NADA prices when I'm selling. It's a great reference for a starting price when you list your bike. But the book goes out the window when I'm buying. That rule of thumb has never failed me and I've bought 5 Goldwings in the last 4 years. In Va. Ct. NY and Pa. And sold 4.
That being said, I've found some folks are led by emotions and will spend more to buy. So the book goes out the window in that case too. We've all done that. Whether a pair of shoes or a Goldwing. For sure NADA pricing has a place and time. It's how you use that info for your benefit. As far as oldwing prices, the demand will dictate the price.