first...welcome to the forum
Second...the value in these trucks lies in 3 areas:
1) the body condition
2) the body condition
3) the body condition
...1/2 ton...3/4 ton...1 ton without a box.
The value is in the front end, specifically the cab condition.
Is it a dually?....if so it does not have a lot of value.
As well, 1 tons are not high value trucks due to their limited ability to be customized, parts availability, comfort, etc, etc, etc.....they are an acquired taste..so to speak.
If I found a really nice 1 ton dually with a flat deck and no rust....I would max out at about $3500....tops....maybe $2500.
Hopefully that helps a little...and again, welcome to the forum.
All good
Coley