What is the best source for donations toward a service trip?

I’m trying to go on a summer service trip to Ecuador or Costa Rica through the group International Student Volunteers, Inc. The trip costs $3,195 not including the $589 in airfare. I’m currently enrolled in college and neither me nor my family can afford anywhere near this amount. I also don’t think I’ll be able to get much money from family or friends. What options for receiving donations does this leave me? According to the ISV group all donations made are tax deductible. What kind of an effect might this have on possible donations?