We can only suggest him finishing his study and start Bitcoin. But if his parents give him the money for monthly, he can start into Bitcoin investment. I heard some students can get a part time job that can give him some money. If he have that two things, having money for monthly from his parents and his salary from his part time job, it will be better for him because he can start Bitcoin investment.
That will take many years before it happen and try to see what he provably missed if he didn't do something at early as this.
So I guess what's better option he could take is to use only the extra funds he get after he take all of those things need to pay. Since somehow accumulating Bitcoin coming from extra funds he got is still the best thing he could do. He could just think about that this is his savings then provably everything will work good after he graduates and find high paying job which provably could make everything good on his side especially on his Bitcoin investment.
If we are still studying and we still rely on our parents' gifts, then we can live frugally and as much as possible set aside money to invest. And indeed there must be sacrifices that we make to do that and one of them if it is pocket money then we must hold back from buying what we want. However, if we want to work part-time, of course that is a solution, but once again there must be sacrifices, because we may be more tired, on the one hand we have to study and on the other hand we have to work part-time. Here our sincerity is really tested, because without sincerity we will never do it. Even when we already have an income, if we are not serious, then everything will be missed too.