Just had a call to say my cars arrived and told me the sat nav upgrade which is a Pioneer AVIC - F860BT is £1200 fitted. I've looked on Amazon and they are £602 and the newer model 960BT is £599 . Should I tell him to **** off and ask if I get the unit how much to fit it ? Seems a bit excessive tbh , any ideas which one is better and what would a car audio garage charge roughly ?