Yeah, $500 would have been a smoking deal! There is an '83 D350 crew on Ebay right now with a Buy It Now of $2100 is anybody is looking for a 2WD.
Buddy of mine just picked up the '85 Crew that was on GSA website in Carlsbad, NM. Got it for $1200 which is a great deal unless it is a total piece. It does run and drive and they said the 4-wheel drive worked good on it. He plans on doing the Cummins conversion as well since he saw what I was doing. I'm jealous he got it so cheap!