Ok at 30 you have a little bit of time before the dreaded "experience commensurate with age" drag curve really starts to bite.
There is another option apart from a full time flying course or a block of flats.
You could use the money to retrain in another career. ie go to uni etc.
Would buying some houses/flats ease your dead end job?
I think that's the real issue, you're in a dead end job that you don't like and you're looking for an escape. Figure out what you genuinely want to do and do that.