I see running , driveable dually trucks for sale on FB often with the original D60 for $1000-$1500 ,it seems the longer wheelbased dually's are harder to sell than a long bed pickup ,so if they have some rot or high miles they sell a lot cheaper...once in a while I see a D60 alone for sale for $500,but its almost always a DRW style..
I was tempted to buy an '84 K30 dually that had a long wheelbase,guy wanted $1500 or B/O ,it was a diesel but he put a carbed 350 in it--had a SM465,dump bed too,but needed floor work and some other minor work--I couldn't see it being a good daily driver/grocery getter though..would have been a good candidate to make into a flat bed to haul cars with or a work truck though..