Good used late model 4x4 loader tractors are in short supply and have been for years. Whether it be JD, Kubota, Mahindra, New Holland, Kioti or whatever, there is just a short supply of nice low hour used machines. Because of that, they bring a premium when they do surface. We occasionally get someone that wants to trade up in size and we will take a unit in trade, but it is rare for it to last a week on the lot. But they do come up occasionally on CL, you just have to keep watching and be ready to purchase when you see one.
I would bet that if the dealers and their salesmen had a list that they could put the "turn downs" on the list that want to try for a used, the week would become hours.