I paid $75 for my SX-980, it had no service sticker, looked new, had no dust but it didn't come with the box. I guess the box makes it NIB not the condition? I bought a Fisher RS-1060 with a box, didn't state NIB, but that I can honestly say looked as though it was never used, it appeared that someone rifled the paperwork from the box and that was that, I mean the cord was still wrapped.
The moral of my story? Expect less and you'll likely do OK. Expect more and you'll probably be disappointed.
There is a seller in Canada who claims to have NOS gear but is charging prices well above and beyond this. There again, gear approaching 30 years old that hasn't been powered up since it's factory test? It's an iffy proposition, you'll probably be looking at replacing a few caps unless you're lucky.