I have to agree with obscsuredfacts. The problem with these deluxe "service" trips is that they are usually more about fulfilling the needs of the rich high schooler than about the needs of the recipient. I don't have any problem if you want to jet off to Africa and spend thousands of dollars to teach English to orphans for a couple of weeks and then head off for a fancy safari. Just don't expect me to applaud you for doing so.
This summer my son did a scuba diving program in the South Pacific. As part of the trip they did a couple of days of carefully orchestrated service work. It didn't hurt anyone, and I'm always in favor of honest work, but to tell the truth they could each have hired a local to do the work in exchange for the money the teens spent on sodas and snacks at the end of the day. I can just envision the admissions eye rolling when some poor kid writes his college essay on his life changing experience painting a school in Fiji. What, we don't have schools with peeling paint here?
My son has learned a whole lot more about the world by volunteering for the last few years at the food pantry in our wealthy town. Working there hasn't cost him a thing other than time. It's opened his eyes to hidden poverty and the struggles people are experiencing in our own back yard.