Two different taxes
Property buyers in Australia deal with two state-level taxes that are easy to confuse.
Transfer duty, widely called stamp duty, is a one-off tax charged when land or certain other property changes hands. It is generally paid by the buyer, around the time of settlement, and is worked out on the dutiable value of the property. That is often the higher of the price and the market value, and for a taxable sale it commonly includes GST.
Land tax is an annual tax on the land a person, company or trust owns in a jurisdiction. It is assessed on the land value rather than the value of buildings, generally excludes the owner's home, and applies once the owner's combined holdings in that jurisdiction pass a threshold.
Both taxes are set by the states and territories, not the Commonwealth. That is why the same purchase can produce very different bills in different places, and why it helps to understand how stamp duty works and how land tax works before you start comparing properties across borders.