So I grew up in Spain (my dad was US Air Force at the time and my mom is from Spain).
Anyways, in there on our high school senior year is customary to have a senior trip. There were two senior classes in my high school and I was president of my class, total of around 60 students boys and girls between both classes. We raised the money to go to Marbella for a whole week, that included train fare, hotel (a nice one too) and money for food and spending money while in there. And no parent had to contribute a penny (peseta), we all worked and raised the money including the stay for one of the teachers (our chaperon) and of course we were mostly unsupervised.
So you have 400+ students, they sure could work to raise the money for their party, after all from now on they have to learn how to be on their own.
My daughter graduated in 2013, our preparation for college for her was to send her back packing around Europe & South America (my wife works for an airline so it was cheap for us to send her) and our daughter enrolled in many workaway places
http://www.workaway.info/ so she could stay for a long time in exchange for her own work. So she spent a whole year traveling and discovering the world totally unsupervised, she even stayed with my parents for a bit but I told them to let her do whatever she wanted and that she had no curfew nor rules. After almost one full year of traveling at age 17/18 we now know that she is ready for college and that she can fend for herself.
So I guess what I'm trying to say is, if you want to teach your kid anything, teach him how to be independent. But I guess I'm the type to kick them out of the nest so they can fly because that's what I did myself, and I'm lucky my wife agrees and encouraged her as well.
First she went to stay with a friend of us in England and two days later she wanted to come back, we had several talks telling her to approach other people her age and make friends, once she did, the transformation happened and she saw what is to fly solo. It was hard to convince her to come back for college but she agreed. Independence and confidence are the best lessons you can teach your kid when making this transition.
Dependence is not a good lesson IMHO and that's what the campaign will teach them if it's successful.
BTW her favorite place, Italy taking care of chickens and collecting olives, feeding other farm animals and going to town at night. She actually learned quite a bit of Italian.