I tell my girlfriend I am going to buy something, but I keep saying that I am not sure which unit I will buy, and therefore tell her a price range which is usually quite broad. Then I buy something and when she asks how much it was, I tell her the price at the top of the range. After she moans about the price, I say, "Would you be happier if I bought the $X unit?" where X is the actual cost of the unit, more in the middle of the range. She says yes, and then I tell her OK, that is what it costs. She has no more steam to argue with, she knows the truth and everyone is happy. Then I wait six months and repeat with the next component.