Silviaguy240,
You're not in my neck of the woods, but I'll give it a shot. Here's what I think:
The car is clean and mostly stock, and I actually like the car, but...
1) It is a 2+2, which is a turn off to most Z owners/buyers. The car was meant to be a 2 seater and that's what most people want. Many don't like the looks of a 2+2, but this one appears to be be clean and without the dreaded terminal cancer. I like this particular car, though, even if I preferential toward the 2 seater.
2) The model year is 1978, which means it still needs to be smogged (in CA) and that makes engine swapping and modifying a bit more difficult. Everything must be smog legal and we would have to pray that it passes smog both a) initially and after modifications are done.
However, since you are not in CA, probably not subject to the same smog laws, the car is probably considered rare in your state, and it has very little rust + being in great shape, I'd think $3000 - $4000 is what someone might pay for the car. However, I'm shooting off my mouth since I'm out here. You would get $2000 in CA for the car. That's it. I hope I'm wrong.
Davy