I agree that maybe this dealer isn't the best. But having worked at one before, I can tell you that (as has been said) modifications, big tires, wheels, and other non-factory stuff don't add any value. In fact, sometimes it's a liability as many customers won't buy something that has non-factory parts on it. Electrical mods scare them off the worst. Please take no offense at this, just stating what I've seen.
Having the XUV out now also probably doesn't help. Even a machine tricked out a much as this HPX won't have the performance a stock XUV has on a test drive.
Given all of this, your best shot is to sell it privately. A nice JD like this in your front yard will sell faster and for more $$$ than on a dealer lot - and you won't have to complete with a XUV for attention.
It's no different that buying a car or truck and a couple years later the new one comes out with more features and power.
Good luck, and I hope you stay Green.