Werdna, I agree and disagree with what you've said
Prep to Year 9 doesn't mean nothing (i.e. it means something - sorry for the double negative), although I agree that it's ridiculous that people might spend $15K in these years, you actually do learn a lot. Even in Year 7, you can sit there and pick out the "smart kids" from the rest of the group and it's no surprise that these kids are the ones who do well in Year 12. Sure, some of them fall out in later years and some others improve, but generally, you can sort of predict who will do well in Year 12. I think that a good foundation is really important in Year 12, especially in Maths and English
Zoned schools are different to selective schools, selective schools select on academic merit, zones select on financial merits. But I do agree, most zoned schools tend to do well, that's why they're zoned. I personally think that they're zoned because they do so well and need to restrict enrolments rather than them doing well because they're zoned. It's debatable
I have to agree with you on the last point though, even though I've attended a good public school (probably one of the best 5-6 public schools in the state), I've really enjoyed my time at school, no matter how you look at it, I feel a sense of pride when I think about how well I have done given the lack of a private school education. It's like that underdog instinct I guess, but apart from just academics, I've actually loved my school's environment, the diverse range of people I've gotten to know as well as the fact that it's co-ed. SERIOUSLY, HOW DO YOU GUYS SURVIVE IN A SINGLE-SEX SCHOOL?! :S like.....?!