Theirs just simply better cars for the money youd have to pay to maintain an SHO, even more if your building on it. That and the only thing the SHO's really had going for them was the yamaha built engine which by now has surely racked up an ungodly amount of miles (along with everything else on the car).
Edit: What I'm getting at with the zero potential is, car is passed its prime, their are better cars for the money, etc, etc, etc.