Im a firm believer in performance mods for the most part lower the value of a car. I think it would be worth as much as a stock version of the same car in excellent (mint) condition. That's just my opinion though. You will get as much as the person buying is willing to give you - I've seen them go for around 11K with less work. I think it's outrageous, but people buy it. So if you think it's worth that much, put it for sale at that much. Don't listen to us about pricing.