Montessori or not

My daughter will be 2 in May and I would like her to go to preschool in September. We've toured a Montessori school and looked so nice. I just wonder if is worth all the money ($700/month for 6 hours a week).

We went to see other schools, and they were messy and dirty. Kids screaming and running in circles. I want my daughter to learn (I'm not looking for a daycare. I'm a stay at home mom).

Any experiences out there?