We are building a 42 sq house (approx) for around $430k with a small sized project builder - that price includes all floor coverings, ducted a/c, facade, moroka to all sides, more windows all over, underground water tank & bushfire protection measures.
I think that puts things a bit into perspective. Around $500 - $700/m2 gets you a structure but you need to spend an additional $250 - $300/m2 (at least ) to add all the trimmings.
That puts total cost somewhere between $750/m2 and $1000/m2 for an average house.
I guess some people are happy to deal with one builder to do everything for the total price. Does it make sense to do the flooring etc. outside of the build contract? Intuition tells me you could save some money, but it would be a lot of extra trouble.