$250, month 25 of a 24-month warranty
An ocean swim drowned the Garmin watch I loved. Garmin was sympathetic, but the warranty had ended weeks earlier. I never checked whether my credit card added 12 more months. By the time I thought of it, that window had closed too.
Lesson:Most premium cards add 12 to 24 months to the manufacturer warranty. Know which card paid, and its claim deadline.