Figuring out your retirement needs

How much savings you need to retire comfortably is a vexing question in the 401(k) era. "What are the chances that you will outlive your days in comfort? Do you have what it takes right now? What happens if you don't make your Number?" wrote Lee Eisenberg in 'The Number: What Do You Need for the Rest of Your Life, and What Will It Cost?' "And, assuming you are not fighting for sheer survival, what are you prepared to give up? Are you open-minded about living in a place that's...