I pay $40 for 45 minutes per week for my DD. It does add up, plus my son has a tutor (wonderful retired school principal) 6 to 9 hours a month ($45 an hour). It all adds up, and my DH sometimes asks where I spend our money?! Not like I'm at Nordstrom buying designer jeans, nope, it's the kids!
To the OP: I am not sure if this is for a child or adult piano lessons.
I was just glad to find a nice teacher for my DD, as she really WANTED to take piano lessons, and kept asking me to get her a teacher. She started at the beginning of fifth grade (this past September), which was a good age in my opinion. I had my DS take lessons for a couple of years, much younger, and he didn't like it, hated to practice.... My DD practices daily without me ever saying anything, so as long as she is motivated and enjoying it, I am glad to give her the opportunity! It is a blessing, but yes $160 a month is a lot to most folks. I'm grateful that my DH provides so we can do this for her (he never had any opportunities like that growing up).