On the http://www.unitedairlines.com.au website, special offers to the US west coast from SYD until mid January are as follows.

A$1099 in T class
A$7999 in Z class

So....the cheapest business class ticket is over 7 times the price of the cheapest economy ticket.

Flights booked from the USA (SFO or LAX) on the other hand

US$998 in T class
US$4110 in Z class

So...the cheapest business class ticket is only 4 times the cheapest economy ticket.

More interesting is that the ex SYD economy fare is about 80% of the ex US fare, whereas the ex SYD business fare is 145% of the ex US fare.

Why is UA discriminating against ex Australian business class travellers?