As for the cost of the licenses, for a PPL, what £5-6000?
minimum 45 hours flying, so you are 6.6666666666666666666666666666667% there!
The only GCSE grades which will be looked at (if you dont do the subjects to A level) will be physics, mathematics and english lang. probably minimum of BBC.
There is a university course which is 3or4
years in length, which takes the student from 0 hours to CPL/IR (fATPL), have a search, its on here somewhere. Enterance requirements are like CC (which is easy peasy!!!)