Surprise, surprise, Dick Smith drop the 32gb version by $100 for their Boxing Day sale, which made it nearly the same price as the 16gb version).
Opening time was 9am, so off I go at 8:45 in the pouring rain.
What happened was:
1) They had opened at 8:30am. Their web site had not been updated.
2) The 32gb version was not $339 in their computer.
I referred the staff to their web site and there was a quick phone call to (I assume) Head Office. I didn't get much sense of what the reply was from Head Office, but they sold me the Nexus 7, 32gb for $339 (as they did to the man who walked in a minute after me).
I now see the web site has reverted back to $439. So it wasn't meant to be in the sale as this is their full retail price.
So thank you Dick Smith.
(I assume they had no legal obligation to sell me the product at that price.)