Don't and you'll be called an asshole. New York is the land of definite opinions. Everyone has a definite opinion about everything. Take them with a couple of grains of salt. No one gets points for being wishy-washy.
Money here is subtle.
There are few big mansions. Expensive buildings and cheap ones look a lot alike. You will have to look closely to tell the difference between expensive clothes and gap clothes on people. That little restaurant may be one of the most exclusive in the city, regardless of the neighborhood. People do not wave their money about, since most people use public transportation or cabs.