What position does your son play?
You are going to get a lot of answers, some wont agree, however, I am a firm believer in if you pay, travel ball, you play.
And you are right, it's a lot of money, and money that can be better spent and I advise parents to save money for college because it's expensive.
Your son also won't get better sitting on the bench. Find out first if he can play in the rec league.
Sit down and have a discussion with your son. I personally see nothing wrong with confronting the person that gladly took your check.