My ds6 is in private school. For us, the "babysitting" factor is definitely key; I need to work full time, and he needs to be somewhere during the day!
I'd love to homeschool, but not only is there the money factor, there's the energy factor. My kid is *very* energetic, and I honestly have a hard time keeping up with him! At his private school, he gets to go from teacher to teacher (they have homerooms but are only there for about an hour and a half a day) and his brain is constantly jumping. I just can't provide that level of stimulation for him at home; it's exhausting for me. I think I could homeschool some kids just fine; mine just doesn't happen to be one of them.
Another thing to consider that school provides extensive interaction with various people away from the all-seeing "parental eye." Not that homeschoolers don't spend time away from their kids -- I know you do! -- but there is, by definition, less time under direct supervision of a parent at school. This has been really good for my ds6 who, as an only child, gets a lot of parental attention and needs to learn he's not the center of the universe! OTOH, this assumes that you're happy with the teachers and the child has some respect for them -- it wasn't that way at my ds6's public K. His private school is much better in this respect.
Ds's school is pretty unusual in that they differentiate across grades for math and reading for all students (my ds6's math class, for example, is first-, second- and third-graders, just starting the fourth grade math book). His school last year didn't differentiate for him, though they promised to "next year" -- but K year was so bad that I *would* have homeschooled if it was my only option. So if the school isn't a good fit, there's no argument for it, IMO.
All in all, even though my ds6 would probably be able to learn more and faster at home, I think he really, really benefits from being in school. It would take an act of some unholy God to make us homeschool (like the evil financial aid gods, *and* the closing of all other private schools in our county). Not because I disagree with the philosophy -- quite the contrary. Just that a good school is *good* for our kid.
