Are NADA prices accurate?

I agree NADA is nearly useless on older motorhomes, particularly when talking about sought after models. They also lump things together WAY too much, for example according to NADA every 1997-2002 sub 30 foot class A motorhome with no slides built built on the P32 chassis has the exact same $15,150 value regardless if it were a entry level Fleetwood Flair with vinyl graphics and particle board cabinets that had an MSRP of $63,000 or an upper end Safari Trek with full body paint, real wood cabinets which had an MSRP of $119,000 when new.