I went on two band trips in high school. The first was to Chicago. The second to St. Louis. They are some of my best memories I've ever had in my life. I know for the first trip, we only needed $100. That included the transportation, hotel, and some fun activites and some meals. I know $100 isn't much, but my parents wouldn't help pay for one penny. If the trip had cost $5000, they wouldn't have helped with a thing. They didn't believe in field trips. We did fundraisers, and I earned every penny by doing fundraisers. I very distintly remember one trip that I had the money earned in the first day. We sold coupon books. They were great. Parents went around to businesses in town and asked for a coupon donation. Some businesses didn't want to donate a coupon and just gave a donation. The coupon books were $5, and they were great. I'm sure $10 could have been asked for them. When my kids get to the point of needing to have fundraisers, this one will be suggested. I will always support kids. But, I hate spending $10 on a roll of wrapping paper and then them only getting $2 of it. With the coupon books, it is something that people use, and the profit is $100. If you live close enough to a mall, you can help put up holiday decorations.
I had a job in high school. I made about $100 a week. I could have very easily paid $800 for a class trip had I saved the money. Maybe they aren't the most educational where they learn a lot about music, but it allows them to play in WDW, which is an honor, I think. Plus, the fundraising and experience are learning experiences. I hope it goes through for you okay.