Freighliner Value

I am going to look at 2005 Freighliner M2 106 truck today. Great condition with only 143000 miles. It may be overkill to pull our fifth wheel but is much cheaper than a newer dually. Anyone know of a site where I can get a value on this truck. NADA does not have these vehicles, Truckpapers and others all seem to have more commercial trucks with dump beds or tanks and for EBay is not showing much.

Thanks for the help.