Thanks guys for all your feedback I am still in two minds. The agent has now readvertised the property and dropped the price slightly so I might be patient with this and see where we end up… 

http://www.realestate.com.au/property-house-vic-noble+park-111169939

I have built before and at 10k per square I personally would not trust the builder and at 20k per square it is a complete rip off…. I would suggest looking at 12k-14k a square if you want a decent finish and want to be happy with the end product…