Prices are what they are. Non-negotiable.
Get the dual chargers if you think you're going to be off the Supercharger network. I've never needed dual charging for charging at home (the car charges fully overnight on 1 charger). Our car has dual chargers and they've been handy off in the sticks. We've never needed it at home (just have a NEMA 14-50 plug).
The 21" tires and wheels are fragile. Be very careful with potholes and road debris. They look terrific, but just a warning. Agreed on the 19" winter wheel/tire setup. We got Rial Luganos and Dunlop snowtires from Tirerack.com.
The P85 is a blast. The AWD cars are definitely nice, but I personally enjoy the RWD experience more. We've got an early 2013 P85 purchased through the CPO program in June.