WAY too subjective. The truck is worth what you will pay for it. If you find one that is EXACTLY what you are looking for what would you pay? $10k? 15? 20?
What about one that needs a little body work or has a run-out motor? 5K?
What about a rat that you have time and money to put into? $1500?
It's like buying a house, do you want something brand new? a fixer upper? Nice neighborhood? good schools?