I have some various comments to add.
1) Some people will always say stay amateur and make more money. Your son has to make a decision. Most of those big amateur tournaments have a very high luck factor involved as to how much money you can come away with. If you find a shot for two days and hope nobody shoots 250 on you in any one game, you've got a shot. On the pro tour, consistency is a key and you need to stay at a very high and disciplined mental level for 6 months, not 6 days.
2) When I was growing up, I always watched the PBA on TV
and dreamed to be a touring pro. I still do. I never dreamed to be "high roller winner" or "super hoinke champ" so those tournaments, although good for money, mean practically nothing to me. I'd rather make $50,000 on tour than $100,000 as an amateur because money isn't my number one priority. Bowling against the best in the world would be. But then again, throwing a bowling ball isn't how I make my living.
3) I would recommend that if your son wants to go out on tour, he bowl some regionals. How can you judge how you match up against the best in the world if you never bowl against the best in the world? Answer: you can't. Sure, it costs $200 a pop and if you cash, you'll have to turn down the money to keep your amateur status. But remember, if he bowls, say, 5 regionals, isn't $1,000 a small investment to make to decide whether or not to make bowling a full-time career? I'd say that if a bowler bowls 5 regionals and doesn't cash in at least 4 of them, and doesn't make the match play cut at least 2 or 3 of those 5 times, that bowler probably shoulnd't be going out on tour just yet. I've bowled 8-9 regionals, cashed in 4-5 and made the cut once (this was about 4 years ago for the most part, so I can't remember the exact numbers). I'm pretty **** sure that's not good enough to survive on tour so I'm not even considering going on tour right now.
4) Go with the gut. If you really want to go out on tour, and have the financial capabilities to sustain yourself over the year without having to worry about losing everything, go for it. Sometimes it's worth it so you don't have to say "What if?" later on in life. For instance, I did not bowl in college because I chose to go to a school that had no team. I went to a grad school that did have a team, mostly beause I didn't want to say "what if?" and see how I could have done in college bowling. 3 years later I was number one in the country. To me, that was worth the shot.