I've come to the conclusion that "rich" is "anyone who makes more money than you".
While I do think that "rich" is a relative term, I don't think this is 100% accurate. I think "rich" is self defined by disposable income past
mandatory expenses. I do think that a HHI of 400k, and 50k nanny, and a private school is rich. If suddenly they changed their priorities they could drop the nanny, the private school, and a few other frivolous things, and then afford to buy a brand new car every month. Hell I almost consider myself rich and my income is only ~50k.