I once heard Rav Yisroel Reisman say, "My wife came home excited that she saved so much money today. I thought to myself, 'if she continues to save so much money, I will go bankrupt soon!'"
Also, in the name of Rav Avigdor Miller, "If you see a sign that says 'save 50 percent,' keep walking, and you could save the other 50 percent also!"