Thank you all for your replies.

We're only having about 35-45 guests and have been quoted anything from 4500-10 000+

The venue I immediately fell in love with when I saw it turned out to be the cheapest! Very surprised (but happy!)

ETA: Sunshine - I would prefer to get married on a Sunday (and still might yet) but my dad, grandparents and a few other relatives that will be attending are coming from interstate so it will have to be in the morning in case they need to be home Sunday night for work the next day if they can't get holidays! Definately not getting married in peak season! Hate the heat, so thinking autumn/winter