Is your son 100% sure?
Has he ever been at the controls of a light aircraft?
Has he considered taking some PPL lessons to start with?
Has he done his class 1 medical initial?
Does he know that pilots work long hours and are poorly paid (at least to start with)... If he is lucky enough to get a gig with easyjet after you've forked out £100k plus the type rating he'll start on something like £1000 a month...
Make sure it's absolutely what he wants to do. And send him down to his local airfiled and get him up in a C152 before anything else.
And if he doesn't know what a C152 is then you're both wasting your time.