You have a 2008 Specialized Rockhopper Disc 29er and a 1999 Trek 6000. You did well on the Specialized. As for the Trek, that's probably exactly what it's worth.
http://bikepedia.com/QuickBike/BikeS...29er&Type=bike
http://bikepedia.com/QuickBike/BikeS...6000&Type=bike