At the first skipped cut, I change the blade. I'm worth it! I use to see there was one class of milk or juice left in the container and I didn't take it thinking the kids or DH may want it. How many times did I see them pour the last glass and never once think I or anyone else may want it? Not one time! I quit guilting myself over having things when I wanted them, including a new rotary blade, even when there still may be some cutting life left.