for a "running and driving" unrestored truck $1000-$3500 also make sure it has a title.
AND make sure the number on the title is also on the truck you buy. Most states used the engine number as the VIN back then and a lot of old vehicles don't have the original engine any more. If the owner didn't re-title after swapping the engine you'll have a ton of hoops to jump through to get it titled after buying it.