My son did not make it to Cary. I believe he was qualifying at 15U? several (like 5) years ago. Our experience:
There was a small attended "cattle call" event (where you paid a fee) to see if you qualified for the next stage. There were several of these around our state.
Then there was a large combine type state event (we paid a fee) to select the "state team" for each age division. I had just read "Outliers" and my son had a January birthday, so I was excited that he was one of the older players in his group at the event....for once.
He made the state team, which then competed at a several day regional event against other states (where you paid another fee and hotel for 2 nights). He performed very well, but didn't make it to the next step which was Cary.
We paid out 3 times....but the total was less than a week long camp we had done locally several years before. The plusses: He got measurables, a USA Baseball t-shirt that we paid for lol, a NTIS "regional" t-shirt which he completely wore out, and made lots of friends that he has played with and against in the years since, many at the college level.
I will say, there was a tad bit of daddy ball, since the head coach of the state team had a pitcher on the team. However, I look back on it as a good summer experience that didn't interfere with other tournaments or plans.
It is a buyer beware if you think your kid is going to Cary NC or going to get recruited. This was only one small cog in the baseball wheel.