Dave Ramsey has run the numbers several times on air. His analysis has shown that you MUST buy it on your 60th birthday, but not before that. Statistically speaking, it is a very slight chance that you would need it before 60, but it is almost gauranteed that you will need it sometime after retirement. The most beneficial time to buy it and maximize the cost / benefit analysis is at the age of 60.
You can do a search on daveramsey.com and find his analysis...
I listen to Dave Ramsey all the time on the radio and heed his advice on many issues.
I am going to his website now to see what that holds.
Thanks for the reminder.