I cannot see RTCC not knowing the price of an Aero S1. Whilst they are a little known for loving the trads more they have sold and serviced dozens of Aero over the years.
I would guess that it was on consignment for someone who needed to sell in a hurry and just wanted the cash? The fact that it went so fast gives me that idea. If they had multiple interests and were looking for the best price they would have hung on and got more I suspect. Price low and lead it into a bidding war is a common technique, if not a fun one.
As for the warranty risk it is not necessarily with the dealer. If it was on consignment it could be sold as seen, especially at that price. Or all they need to do is sell one of the many aftermarket warranty's and the pain is out of their hands in most cases. I had an authorised Porsche Centre do just that to me years ago.
