It's worth whatever someone will pay for it really, if interested, speak with the current owner, get all the details, then try to make a deal you think is fair. I've seen me go for a lot less, and a little more.
I'd get it just because my first real guitar was an '83 version, when I was 16. I'm sure if I had kept it, might be worth something ha ha...just like Phil Collens version back in the day. Hell its only 300!