NADA is a good start to compare, but it is what it is. There is much more than the sold price in a MH: cleanliness, condition, tire, options, milleage and the "smell", some are disgusting and not curable.
You will rarely find a MH with a asking price that match the NADA average retail, the NADA prices are sold price, negociated price, same with PPL. I once got $10,000 off over the phone on a $50,000 Allegro sold by PPL.
I sold a Truck Camper $23500, NADA was $26700 average retail but the average asking price for these where around $25000, I doubt I could have got over 25000. I bought a Monaco Cayman DP 2003 and paid 35000 after a good negociation, NADA said average 30,000. After a year checking the internet and looking at MH, I never saw a Cayman 2003 at that starting price. If you want to pay NADA average retail, be prepare to negociate.
Monaco Cayman 34 2003, Cummins 300HP
Bigfoot 2008, 10.4, F350, 2006, Diesel 6.0, Black, 4x4, long box, Air lift, Rancho 9000, Rear sway bar.