http://www.edmunds.com/ give them a try and enter your info. you can also try Kellys Blue Book. Best of luck, hope this helps. Cheers

Yes, either edmunds or www.kbb.com.  However, new vehicles depreciate most in their first year of ownership.  Expect to have lost about $10-12k from retail value on this truck, based on what I'm seeing here locally for resale value of similar vehicles.  

You say "no extras," and lack of 4WD, power windows, etc., with a base v6 engine will hurt resale value even more.