Travelers entering Australia can bring in cigars duty-free under the passenger concessions scheme, but strict limits apply:
If you exceed this allowance, you must declare the entire quantity and pay duty on all cigars at the full commercial import rate. There is no duty-free threshold for the excess—you pay on the whole lot.
Australia's biosecurity and customs enforcement is rigorous. When in doubt, declare—it's faster than dealing with fines or seizure.