Age 12-13. Child was playing on a very good travel team but was more serious about soccer than other teammates. Child wanted to try out for a more competitive team but realized he/she needed sharper skills to move to a significantly better team.
We paid for a one hour private lesson about once a week ($75) for about a year on top of club practice commitments. Training was provided by recent D1 college player.
Our child showed up at tryouts for a very top local team and was offered a spot on the roster after 15 minutes of tryouts.
I think private lessons is a waste of time and money until your kid makes the decision that intense additional training (can even be group training rather than private training) is what he/she wants in order to reach his/her goals as a soccer player.