In a recent survey, non-retired adults told investment firm Schroders that they will need approximately $5,000 per month "to enjoy a comfortable retirement." But is that really enough? Maybe! Studies and surveys like these make for eye-catching headlines, but they skimp on the details. For example, where are these retirees planning on living? $5,000 per month is going to go a lot further in, say, Kansas City than it will on the coasts.