The replaced items listed are all fairly common repair items, but they don't have anything to do with maintenance. Replacement glow plugs should be Motorcraft; if not (esp. if they're Autolite), I'd consider replacing them again. Bad/cheap ones can swell and get stuck in the head. Ideally, replacement CPS should be one from IH. For maintenance, determine how often the oil and coolant have been changed, what kind of oil/filters have been used, and whether the OP has kept an eye on the anti-cavitation level in the coolant.
Plow mount means he's pushed this truck; def. not worth the asking price.
Re. the rust talk in the other thread - wear a glove when you run your finger in the bed wheel wells; you DON'T wanna cut yourself on rusty metal. Also check the rear fuel tank, esp. where the bottom sits directly on the skid plates (perfect set-up for rust). And the biggie (expensive to replace) - check the radiator header for rust.