I've got an interview tomorrow for a teaching position at a private school for kids. In a phone conversation to an HR lady I asked about the salary and it's the minimal salary in my region. Then I was lectured on how I should not show at the upcoming interview that I care more about the money than about the children. I want to let them know that I actually do care about the money, but I want to say it in the most polite and professional way. What do I say?