If the trailer is, in fact, an unused untitled unit, the price is very good. IMO The NADA values are for used units, and even at that the price is below used. You also have to consider that a new HiLo is a one of a kind thing and probability of ever getting a new one in the future looks rather dim.
Added Note: You realize that there will be no warranty on the trailer itself, but you may be able to get warranties on the appliances. I'm not sure how those would be handled, it would be good to ask the dealer.
My Great Wife Joyce
2018 Jayco Jay Flight 21QB
Formerly owned 1705T and 2310H
2012 F150 4X4 SuperCrew EcoBoost w/Leer Cap
Reese WD Strait-Line Hitch
Amateur Radio K3EXU