searching for an exchange partner in england for 3 month!

I´m 15 years old and i live in germany. at the moment i´m searching for an exchange partner in england. I will go in 2010 for 3 month.
I think it´s more expensive if a girl come to us and i can go to her. Also i will go to school there. I hope someone will give me an answer!
greetings chrisbi