As far as I know in normal autions where you can bid to items there is 18 items a day (6-24).
And in that period you can see 2 gold, 5 silver and 13 bronz each day.

In test server I found 3 gold, 4 silver and 13 bronz last day.
I just created a picture about the 3 gold.

Sorry my bad I was a bit tired.
It's was the normal 11 bronz as it suppose to be.

Just one silver item converted to gold the rest is good