There is a safe-ish middle ground when it comes to select ball. Unfortunately, not all rec leagues are strong enough to develop much talent, if your son is looking to play ball in high school. (Notice I said high school, not college. Just assume that high school is the furthest up he's going to get, and if he goes further then that's great.)
However, on to the other extreme from rec ball, you have the travel teams where parents invest 10s of thousands of dollars per year and travel all over the country all throughout the year. To me, that's just ridiculous. You can find good, solid programs where you don't have to put so much time and $$ into them. I don't know where you live, but in the DFW area, both of my sons have played ball for years and we have only traveled out of the metroplex once for a tournament (to Round Rock).
Personally, I think 9 years old is a little young, but what do I know. My sons played rec ball until 11U and 12U, respectively then select ball. My oldest never played after high school and my youngest is a sophomore, so who knows what will happen. But my expectations definitely aren't on him playing ball past high school.
And in summary, you'll have a really good time at the ball park for the next few years...just don't make any plans on Saturdays and Sundays for a long time. The way pool play/bracket play works...you really never know what your weekend schedule is going to be like so just tell everyone not to invite you anywhere until your kid is in high school.
EDIT to add: another poster was 100% correct in stating that your kids will be expected to play summer ball once they get to HS. You don't play in the summer, you probably aren't going to play in the spring. And if you don't play football, then you practice all Fall, or play Fall ball if your school participates in it. Ours does, but not many around us do. It isn't UIL sanctioned, so the baseball coaches technically can't have anything to do with it.
*Sigh* so many edits.