If it's a 1 1/2 ton then $1,000 is about right.
If it's a 1/2 or 3/4 ton then it might be worth the $2,000. I bought a 1940 1/2 ton for $1,000 that was beat more than a red headed step child. Original sheet metal on a 40 is getting hard to find, and a complete original even harder to come by especially if it's strait.
It's your money, the rest of us only have opinions left after buying our trucks.
As far as sitting, I bought a 46 1 ton last summer that had been sitting that long. Cleaned it up, changed the oil, and it fired right up.