Not sure what we have spent but it would be over a thousand now, doing all the labour ourselves. It's probably only about 7-8m2 but the steps and need for stumps adds cost. The blackbutt was expensive at $6.30 a metre, we could have done silvertop ash or the cypress for about $4.?? a metre. The place where we got it had a special on the silvertop due to over supply but I felt the blackbutt was a better match to the cypress on the rest of the house and it's only a small deck so the difference was worth it. We will likely use the lighter cheaper silvertop for the back deck as it's much bigger.
Rough break down:
Blackbutt $620 including about $50 off for an "old builder discount" that my FIL negotiated
Concrete $130 I think we used about 16 bags in the end
Structural treated pine $200
Dyna bolts, nails etc $30
The H4 posts were free because FIL had them laying around
Still to add on stainless steel screws that I'll pay FIL back for, not sure what they cost but they're not cheap.
Then oil or some other coating.