If you have $3 million, you undoubtedly have a lot of money — and more than most people ever will. However, before you jump into retiring and living off the cash, you need to do some math first.

For one Redditor, there is a concern based on a post in r/fatFIRE that they don’t want to be cash poor after buying a multi-million-dollar home. The goal of this individual is to buy a co-op in ...