personally, I think $12,000 is a little high. A freind of mine sold a red and black 5 speed in good condition with a complete set of extra decals for $3500 about 4 years ago. It had teh center console plaque and everything, just had a set of extra 10th anniversary decals because previous owner had contemplated painting it.
it wasnt in as good of shape as your car, but for the extra 8.5K, it could have easily been restored to factory new condition.
That's one nice Z. I have a Gold and Black that I bought on Ebay that I'm doing a restore,but the good thing it's rust free. I would put it on Ebay and try it because the red and blacks are more rare. The Gold ones are going for anywhere from 7000 to 28,000 for extremely low miles. You don't see the red and black ones much on there. VGood Luck On Your Sale!