Is paying $1538 USD per month considered expensive for a private middle/high school?
Expensive, but not outrageous. Of course, it all depends on the area you live in. When I lived in Southern California, I paid $11-1200 per month USD for my son’s private elementary; his middle and high school would be right about the figure you’ve stated. It was an excellent school, though, and completely worth it. I now live in the midwest, and only the most exclusive (and overpriced) schools cost that much. Most in our current area are around $4-6,000 per year. However, I can say that most of them are not nearly as good as the one in So Cal. It all depends on where you are and how good the school is.