I've built twice now....

First house was 170m, and $170,000 to build, basic cost, with no extras..
Second was 230m, and $230,000, basic cost, no extras..

Since the $24,000 grant, the prices here are REALLY exxy, our house to build now was $320,000... a hundred K difference!!

We spent around another $50,000 on extras, like fencing, reverse cycle ducted cooling/heating, down lights etc..

Here you can pay extra and have your plans fast tracked, only took about 2 weeks. First house took 18 months... slow, but GREAT work... 2nd house took just under 9 months, again great work. Depends if all the materials you want are easy to obtain, and where your building isn't rainy or such too!!