I paid 6k for mine, engineered as is. (No Simmons though). Reasonable condition, a few little spots of rust coming through the 2pac paint though. I recon thats about what it was worth. Everyone who has done the conversion tells me how cheep I got it. All depends on your view point.
It would have to be something special to get 10 grand for it.
There was a red 1G-GTE RA28 for sale at the last dyno day Looked like a really neat car, I think he wanted 9k for that