Him dropping out of college to pursue bodybuilding was a mistake. He could have gotten an education while eating at the all you can eat dining hall and training in the included gym with all the college girls. Bodybuilding and college are not mutually exclusive Idiot
Making a living from bodybuilding is a risk for sure. I'd probably say he'd do better if he sold steroids and did personal training on the side, while pursuing bodybuilding. I'm not sure if bodybuilders can get $50 USD per hour or more for personal training, and schedule 40 hour weeks at that rate - that would be $2,000 a week, which is $104,000 per year. Add that to a supplement sponsorship if he can get one, and whatever gear he can sell on the side, and he could push that figure up.
If he does that without abusing his body as much as someone like Dallas McCarver did, for example, then bodybuilding might work out for him.
I'm just trying to think of what way this young bodybuilder could play it to make it worth exclusively pursuing bodybuilding. Even Georges St-Pierre said on a recent podcast that he tells the parents of children who aspire to be UFC fighters that it's not worth doing [presumably because it's so "Feast or Famine" in the UFC, much like in bodybuilding].
The Top 10 bodybuilders in the world can all make six figures, with the top 2-3, maybe top 2-4, making $500,000 to $1,000,000+ per year. For example, Ronnie Coleman, Jay Cutler, and probably Gunter Schlierkamp were likely all making $750,000 or more per year.
But bodybuilding is a big risk, and I agree with you about it not being wise to drop out of college to pursue it. But if he juices intelligently without overdoing it horribly, gets on board with a decent sponsor, and makes money on the side from person training, selling gear, and potentially nutrition coaching [if he has the intelligence to do it], he can do well.
I hate to recommend that anyone sell gear as an income stream, but now that I know the truth of how little money there is in bodybuilding and how many competitive bodybuilders do sell gear, I am not so naive about it. It was Gregg Valentino who said that all bodybuilders sell gear, and while that is probably hyperbole, it wouldn't shock me if some huge number, like one third of bodybuilders or something, actually do sell gear.