Cooleo, another option might be to take up gliding. It's a cost effective way to get into the air and learn how to fly.
I fly from your local, or one of your, local gliding airfields (but don't glide myself) and they offer a Cadet scheme. It costs £40/yr and, I believe, instruction is free and you pay for the winch or aerotow launches you use, this would need to be confirmed. You can get solo when you turn 16. PM me if you would like more information.
I'm sure other gliding clubs may offer something similar so it may be something for you to investigate further.