Your target audience doesn't have $4200 to spend on a toy?
I have to say though a big x2 to what both Jim and John said.
People don't like issues. Honesty is good. But my thought would be, "If this guy isn't going to take the time to get the diff sealed what else has he not taken care of." Granted there are some things that will always be an issue and are to be expected on a trail rig.
People don't like the only pictures of the vehicle being that of it being beat on. It's kinda like a stripper. We all know their purpose in life. But she isn't going to get the pass by Mom if the only pictures you have of her are her swinging on a pole.