2WD or 4WD?
I have the same year model truck. That freaking oil
Pan is known to leak as I have the exact same issue on mine. The dealer quoted me $1,900 to replace the gasket and I laughed. It is some work to get the oil pan off as there are items in the way but not $1,900 worth. I bought a new oil pan and gasket and plan to replace it myself one good weather weekend.
Good luck with sale. They are some good trucks. I have 228k miles on mine with no major issues other than a new starter I had to replace last year.