You should drive it. Get it on the highway, take it through the paces. Check all the fluids. Check the compression. Make sure the transfer case engages correctly. Look for leaks. The positive terminal on the battery looks a little scary to me - where are all those wires headed? If the truck really is rust free, drives well, and runs good - then I wouldn't have any problems paying 7k. 6K would be better, but trucks hovering around the 5-6k mark are getting real hard to find, in decent condition - especially with all the hipsters snatching them up.