Can't ball park any kind of number without some description of what you're looking at and where. It's a Dodge, so most of the value is about the rust. Front fender heels and bed wheel arches are common spots but pretty straight forward fixes. When the floors and the rockers go, they take the end of the cab mounts with them, some fab required. Rad supports are a common problem and if 79/80, real hard to find replacements. Frame rail next to the gas tank is another spot to check. Factory original roll bars are very few and far between. Most common engine in any tin grille was the 318, so I'd pay up for something bigger. 440 is obviously the holy grail. Wasted interior plastic isn't a show stopper but can be a bargaining chip.

For one that's in rough condition, I price it based on the value of everything that's worth keeping. If I was starting with an empty parking spot, what would I spend to get this far buying it by the part. For something in solid condition, I price it based on how much it's not gonna cost at the body shop. Doing a clone isn't gonna cost any more than fixing an original so again, I'd only pay up for the option code on the equipment label if still present. It's a 1/2 ton 4x4 with a graphics package that a couple places repop.