With 100 hours it is worth $9,752. With 5,000 hours it is worth $1,816. If it does not have 4wd subtract $589. If it has a canopy add $123. If it has a loader add $3,400. Who knows as you left out condition, hours, transmission. In 1997 the 870 2wd cost $12,800 and the loader was $3,400. http://www.tractorhouse.com/list/list.aspx?manu=JOHN+DEERE&mdltxt=870