Here's my take on it.......I think she burst into tears not because you were being unreasonable about saving money but because she and some of her friends may have already talked about how nice it would be to go to the new theater and see what it's like. For some reason it almost seems like once a teenage girl gets her heart set on something it's hard to change her mind.
If she and the other girls have their own money and want to spend it on the tickets to realize their dream that's fine but otherwise they should take your advice and go to the less expensive theater. Oh and by the way, can they throw a few candy bars in their purses?
You're a good mom to be a part of this and to be willing to take the girls.