South Africa Cape Town Trip

I would love to go on a high scool trip to South Africa. We are going to Cape Town in South Africa in 2016 to help the people in Welcome Primary school. My school and Welcome school are linked and students from my school have been going once a year to help build houses. We have already connected them to the internet and the kids over there regularly skype and email us. The trip costs £1800 total and we will be staying in Cape Town for 12 days before returning home. Everyone who has been on this trip before has said it has been a life changing experience as you get to see how little they have and it makes them realise how privileged we are. We will be helping them out by bringing them basic things for the kids like toys, balls, books and other school supplies. I really can't afford this so please help me. Anything will help.