I would agree with Ed's assesment. Like all things, especially in todays economy, it is worth what the buyer is willing to pay for it. Another factor would be the condition of the battery. If it has an excellent battery then good, if the battery is on it's last legs then you need to add about $5,500 to what you are willing to pay for the truck so that you can replace the battery.
As far as what it might be worth in 5 years you may want to ask a resident of Fort Myers, FL or Las Vegas what they thought their house would be worth in 2008 when it was purchased in 2003.