You can apply China tourist visa from the Chinese embassy in Australia with the following documents:
a. One completed Visa Application Form with a passport photograph attached;
b. Your passport with at least 6-month validity and at least 2 blank visa pages.
C. round-way air tickets and hotel booking.
A normal visa processing procedure takes 4 working days, as for the cost, you can get it here:
https://www.travelchinaguide.com/embassy/australia.htm