What I can tell you is that after PPL you may start studying ATPL theory in DL and whilst working so that you may earn some money on your own while living at your parents'.
After that you go somewhere cheap for hour building like the USA, Spain, Portugal, or somewhere in Eastern Europe like Latvia, Poland, Croatia...
Also you can take your CPL, ME and IR somewhere cheaper than the UK. For example Poland!
Obtaining American licences and ratings and then convert them may turn out to be more expensive than directly obtaining european licences and ratings.