Remember, NADA = North American DEALERS Association.
So, you'll find their evals of ANY vehicle is higher than what it's true worth is. And true worth is what a willing seller and a willing buyer agree too.
I use to test NADA values against Blue Book for cars back in the days when I bought a new-2-me used vehicle every 2 years and they were generally 15% higher then the Blue Book. Most savvy buyers wouldn't pay higher than Blue Book prices but would price their vehicles when they sold them at NADA value.
I would say if you do find a NADA price for any rig, you wouldn't want to pay that much.