I was about to say exactly what Phil said. The main reason the stealer has offered you 12k is because added extras and aftermarket modifications add absolutely nothing to a PX price. I would guess that every dealership will tell you this. Similarly, many people looking in the private market have taken this to be a universal principle of selling a used car, thus it can be difficult to get a price the car is actually 'worth' in reality; unless someone is looking for exactly what you have done to your ED 30, in which case they would obviously be willing to fork out. Personally if you do decide to sell I would get it as close to stock as you can, and earn a bit of money back from your mods - particularly those which aren't a big hassle to remove and replace.
