At present, Ancient Greek is offerred as an option beginning in Year 7. You have to show that you are good at Latin before you can take this option, and you do have to make some hard choices about subjects that you will not be able to study.
What makes Greek worth studying?
All that you've read about Classics is true of Greek, but here are some special reasons...
Greek is at the root of a lot of technical vocabulary, especially in medicine.
Greek has its own alphabet, which makes it a puzzle to unravel, and a mystery to your friends.
You can impress your next school with an even broader knowledge of languages than normal.