Whilst it is probably ideal to do it all in one go, there are lots of advantages doing a bit at a time. It will introduce you to a club and people in it. Remember you get most out of life from WHO you know. Why not see if you can get a part time job in a flying club, odd jobs for flying hours etc. You may be able to join others on trips etc and get a bit of hands on even if it doesn't count towards the hours. Go for a flying scholarship, the RAF don't do many these days but they still do a few along with GAPAN and the Air League.