This looks like a nice one - VERY cheap as Simon says
I didn't say it was "VERY cheap", I said "it does seem good value", there is quite a difference.

Furthermore, I agree, it is probably on target, or more, than he would be offered by a dealer. Many of the S1s that come up for sale privately are offered at dealer money which seems unrealistic to me; why buy private when you can buy from a dealer at the same price and have the legal safety net?
If it checks out, it is good value; if the history isn't up to date, or patchy and the car is less than perfect, it would not be. The S1 is the most challenging of the Aero range to keep in good condition due to the limitations inbuilt at the design stage. It simply wasn't designed with maintenance and ease of service in mind - it was built more toward a racing car design (hence the appeal to some). For this reason, S1s are not always what they seem and can cost more to keep in tip top condition than other Aero models.