Does the GPS on iPhone 4S cost?

I have an iPhone 4S we travel a ton and last week, we forgot to bring our GPS and used my phones GPS. My data plan is the smallest you can get, does it take a lot of my data or charge money? I need to know because I'm afraid that I will do it again. Please let me know. Also if it does cost how much does it cost?

The MotionX GPS cost $0.99 it doesn't use much data and it only charges one fee to buy it… Plus it's really good!