At $.10 a blade, and shaving every 2-3 days, my rule is 2 uses & out. I like a fresh blade. At my age, with a stockpile of 700 IP Red and Astra SP blades, I won't live long enough to use them all. The cost of blades are insignificant compared to DE's, brushes & soaps. I probably have more loose change fall out of my pocket than I spend on blades a year.