During the height of the boom I would have advised against going to OAA.
Doing it right now is pure insanity. Save yourself and your son a ton of grief (and money). Put the plans on ice for the time being. If he has ants in his pants and wishes to start doing something, then get cracking with the ground school at a modular school. There are very good schools dotted across Europe where you can get your training done for a fraction of the price and be just as airline ready (if not more) than going to one of these major schools.
I speak from personal experience, good luck