1. Some action is not justified because it will not elicit a valuable or positive enough response. Mom can be so volatile, that's why I'm always hesitant to call her. I mean, if she's going to start yelling at me, then it's not worth it to me.

2. Some thing is not as valuable or important as someone thinks. A: "Oh my gosh, I'm so sorry I spilled wine on your rug! I'll pay to have it cleaned!" B: "Oh, this old thing? Please, it's not worth it."