I certainly paid more than blue book for mine. But it came with an aluminum block with upgraded internals and whatnot. Basically all the boltons and a 2.3l Whipple.
I bought mine in Sept of 03 with 1400 miles on it for 29k. I would not say I stole it by any means but beings the dealers around here were getting 5-6k over sticker I felt at the time I did pretty good. My car right now only has 12k miles on it and I have thought about selling it but I know I could never replace it since it still looks new and even smells new when you open a door on it.
I paid $15K for my 1 owner 2003 mineral grey cobra coupe with 49K miles. It came with a Kenne Bell 2.6H and a Magnum T56 transmission. Also it came with the stock T56 trans which I sold as well as an extra set of black chrome FR500's with tires. Basically after selling all the extra parts that came with the car, I ended up paying around 13K or a little bit less.