I do not understand you putting the cart on front of the horse.
I would never talk price on a auto when there is an apparent problem with the vin plate not matching the truck.
For even if you bought it at your price what are you going to do with a truck you can not get title to and register?
It was also clear that the GVW rating on the vin plate was for a 1/2 ton not a 2 ton truck.