Ehhh... Sorry if I don't get it, but why is that a bad thing if you're already exporting those?
I would not be surprised that we were selling our building materials at a lesser price than what is being charged here. We essentially have only two building suppliers and despite their denials, I think there's a bit of fixing going on.
A few years ago independent building material supplier was told by these firms that should he continue to supply wallboard imported from China, then other building materials they supplied to him might have slow delivery times if at all.
I think our's and Australia's problems lie in things like price gouging than the status of our trade relationship with China. Eg I'm currently getting my house built on the cost of materials plus 10% based on an open book contract. I noticed the council had increased my building consent costs by 40%. When I asked the council for justification, they in turn blamed covid. I asked them did they outsource my house plans to China for number crunching and they sent the reply back in a containership to arrive at a price increase of $4326.