That does not look good at all if I see it correctly, and being at 57% already. The question is, do you have a nearby place that is a part of the battery replacement program. I did not with my iPhone 5.
Yes, I would get it if it's eligible. Your battery usage could very well start to decline since your battery is affected by this known problem. Call Apple if you don't live near an Apple Store. Many cities have authorized retailers such as Simply Mac that can handle standard warranty Apple Care claims such as this one.