[jhv48]

Good points by all. If this is not an impulse buy, you'll be happy with the car for many years to come. But, when it comes time to sell it, the color will limit the appeal somewhat. Having said that, it is definitely a striking combo and will attract attention wherever you drive it. The purists will poo poo the color, but if it pleases you, who cares. Those same purists drive a replica/kit car too.
So, I would do as others have said, make a lower offer and sit on it. He might have problems of his own selling it and this is not the best time of year to sell a cobra. You might pickup a bargain.