Great Barrier Island trip

At school I have been given the opportunity to go on a trip to Great Barrier Island for 16 nights and do various water and bush activitys such as sea kyaking, surf kayaking, fishing, hiking, absailing, rock climbing, 4/16 nights to go stay anywhere on the island, walking through rivers with ropes, swiming and many more. The trip has been offered to about 40 students that are high achivers in physical education and we are also involved in the trials for the schools top P.E. class. The trip is going to cost me $1750 and I am doing everything i can to save that money. I need to have a $500 deposit in on October 1st 2015 or I will miss out on this amazing opportunity!!! your help is much appreciated thanks!!!