As a teacher I can tell you that schools are a LONG hill to climb. Nearly all schools (like mine) make a multi year contract with either Coke or Pepsi. (Mine was Pepsi) However the state has now thrown out "Pepsi" in the machines so Pepsi is scrambleing to find other things to put in. Trust me.... they are real crap what is going in. All the machines are filled with 200z plastic bottles.
Glass bottles will NOT work. Cans... might but plastic would be preferred.
You WON"T outbid the big boys.
The kids would LOVE our drinks, but not much chance as you can see to get into large school districts.
NOW.... that does NOT mean it is not worth a try. You never know what you might be able to pull off. However note what will need to be done with plastic bottles or cans. I can not see a place for glass bottles at any school. Especially Elementary. (I am in High School, not much better there. Lets not arm them any more than they already are... )