Well, _nothing_ about flying is cheap...
Here are a few ideas:
1. Join the Air Cadets - free flying a few times a year, and (usually) good instruction on ground subjects.
2. Later, try to join Aunt Betty's flying club [university section] - the University Air Squadrons are excellent training grounds (I hear), but require high standards and committment.
3. Consider cheaper forms of flying, for example gliding and microlights.
4. Consider the new National PPL - but only after you have checked out the costs of transferring to the JAR-PPL if you want to go flying as a career.
5. Find rich and feckless relations! (I'll be subbing _part_ of my daughter's PPL after she's done her GCSEs).
Hope those un-connected thoughts help!
(Edited for innumeracy...)