[Secret Agent Man]

Easy. These women only have to live that way a short while, then inherit the money they never made, and then their fun life begins.

[boop]

You'll see a rich old man with a beautiful young wife, but you'll never see a poor old man with a beautiful young wife.

My guess is the "rich old men" can afford medicine and doctors that keep them alive longer. Well, that and the young arm candy.