1976 GMC Sierra 2500 4X4

[Steve1954]

Note: Admins, I guess I violated the rules by posting a "What's it worth". I apologize. If you need to remove, please do so and I will get compliant.
Note 2: Admins, I became compliant and became a premium member. - Thanks for your help mongocanfly.
Friend has a '76 Sierra Regular Cab 2500 4X4. He says its worth $15,000.
From My perspective, it is a mess. I told him that in the current condition it is worth exactly dick.

a) It was a basic red and had a silver "splash" painted on the side, which looks nice from a distance, but you can see and feel where the guy pulled the tape off - not original paint and not a great paint job at that.
b) he decided to "rewire" it, pulled out all the old wiring and bought a wiring kit (and then a second wiring kit) did not finish.
Ever see the movie "Gremlins"? Wiring is everywhere and nothing is connected.
c) he took all the door, floor, ceiling, dash panels and lights off in the cab to replace the wire (i know you have to). All those panels are spread out all over the garage. And many are broken.
d) I found the frame to the instrument panel .. . . and the speedometer cable . . but no speedometer, no gauges.
e) steering column is unbolted and laying in the seat - bolts not found
f) tail lights are hanging by the wires
g) truck has not been started in five years.
h) tires sat flat in the garage for at least 5 years

ok. maybe not "exactly dick" but my research indicates a good wiring kit is $750 and it cost another $750 to get it installed. And once it is running (if the engine even starts) it needs a safety inspection and registration. And it is going to need a new set of tires probably pretty soon which could be $600.
And when you get to that point, it is not a "classic" but it would be a pretty "daily driver" until the engine starts to go from sitting for 5 years.

My question is once it is running, what is it worth? (my guess is about $6,000)
What is is worth as it sits?
Would I get the $2 or $3 grand I am going to put into it out of it?
- or am I going to be driving a pretty daily driver for a while?