I went on my first trip away from home in 5th grade. My school went on a week long trip (M-F) to an environmental camp. It was a lot of fun. The only time there was no chaperone around was when you were in your room at night to sleep. You went on adventures with a guide and a teacher, you ate with a teacher, and the teachers had rooms in the same building as you. They even put masking tape on the outside of your room door at night so that if you tried to leave, they knew. I went on the same trip again in 6th grade and on a trip to a similar place again in 7th grade. Each time my class went in the winter so we got to hike around in the snow and go snow tubing and cross country skiing. Some groups go to do snow shoeing but mine never did. We also got to cross a couple cable bridges and do trust activities. We learned about the environment and got to see a real compost center. For meals, one person was the dedicated Kitchen Patrol. They had to get the food, refill your drinks, and clean up when done. Everyone at your table had to do this at least once.
In 8th grade we went took a 1 night trip to Washington DC. There you could go around the museums without chaperones but you had meeting times. We also did tours but once again you had a teacher about every 6 kids. And you were so busy each day that you had no time to goof off.
Each trip was paid beforehand. You could bring money for souveniers and for the snack cart. Sorry but these trips were in the pre-cell phone era, so I can't comment on that.

My parents had no problem letting me go. My school had been doing that same trip for years with no problems. Parents were given months notice and packets of details about the trips. The chaperones were always around, you were seriously never alone. The kids were even allowed to sell candy to fundraise their trip. (I think it was like $250 anyways, so a great deal!)
Other than badly spraining my ankle Thursday afternoon on the 7th grade trip, I had a blast!. (There was a dance Thursday night and I couldn't dance!

I also had to hobble around for the last day.) I really enjoyed those trips and never had a problem being away from home. I was with my friends, away from my parents, playing around in the snow for a week. What could have been better than that?