One of the great turns of phrases that I picked up from another coach years ago goes, "The thing about seeking exposure in baseball is, you might get exposure, but you might get EXPOSED."
Meaning, a lot of people go out there and do the recruiting events including showcases and tournaments and they assume that if they work the system hard enough things will happen. This is actually a cynical view of recruiting, i.e., the belief that you can buy your way into a college roster spot.
But while a talented player needs to get exposure, for a less than talented player, you might be paying just to get exposed -- and written off. And continuing the process will only empty your bank account with nothing but frustration to show for it.
If your son is a talented player, then I think one year from now is plenty soon enough to do any showcasing. And I would add that if he does a PG event, there's really no reason to do any others, because when you're done you'll have a player web page with a reliable scouting report posted for all to see. Just be sure he's ready for that day when it comes, so that he shows well and gets the report you are hoping for. One PG event per year will document his measurables and also result in his web page showing his progress (or lack thereof).
If your son is really just going to enjoy HS ball and is not really a college (or pro) prospect, then showcasing is not for you. If you feel you are knowledgeable enough and objective enough to make that assessment yourself, great. For most players, it's advisable to ask someone knowledgeable and who is willing to tell it to you straight.
To clarify, that's as to showcases. Tournaments are another thing altogether. Play all the tournaments you like. It's a game, and it's supposed to be played! If something further comes of it, great. If nothing more than the opportunity to play more right here and right now comes of it, then I say, enjoy it while it lasts. It all ends too soon, so grab all the games you can while you can.