Alright, is the 1200 for just the engine? If so, I agree with Gary, too much cash, I think most here would suggest you never go over about 600-700 even for a running engine, just a little more than core value because you just don't know till you dig into it. If it's for the truck even with the rusted out body, you can make some more cash off of some of the parts, especially if it's a 4X4 with a ZF-5 manual. The body should have some scrap value too, it might still be a little high but not as bad, especially if you can talk him down to 1000. Also take the oil filler cap off and run the engine, is there a lot of crankcase vapor there? If not that's a really good sign that it's a good runner and will remain so for awhile.