To use your car analogy- just because a new car will be worth more than a used one (and this is much more true of cars than houses), that doesn't mean there's no such thing as a luxery car. Sure, newness is a type of luxery (I'm not sure how much housing price depreciates with time, but I'll believe you on this one), but new houses can be built to cater to wealthy buyers or to cater to lower income buyers.