I bought a 15 Denali 3500 dually, Duramax, 4X4 for less than $57K new. I know the new ones have gone up and along with it the used ones, but, my gosh, that is a bit stout. I must admit my GMC did hold it's value very well when I traded for my new Ford. The real dollar trade price was only a couple thousand less than I felt I could have sold it for myself. I saw it listed on the dealer's website for $52K. It did have 41K miles on it but was in super shape and also had some nice upgrades like a bed cover and Titan 60 gallon fuel tank.
Glad he moved on.