If you're a bit worried about the price skyrocket I would cut back on the following as you can still spec change.
Comfort access - For 1.5k you can stick the keyfob in the dash.
PPK - 2k for a chip for 15kW is just not worth it. A procede/JB4 can easily removed (physically) without any evidence the car has has a piggyback tuned. They're basically plug and play.
Heated seats - Don't need if you don't have hemroids :P