How much does color stripping/rust removal usually cost?

My hair is about the middle of my back, and my roots have grown out 2 or 3 inches, I’m just wondering how much either rust removal (my hairdresser suggested it to help remove old color) or stripping costs…it differs in a small town compared to a big city, right?

around here, it would cost around $50. && i live in a rly tiny town.