Where there is a relationship between the two parties (such as a sale between parents to children or brother to sister or vice versa) , then often the sale is deemed to be not at arm’s length.
Then we can help by providing a property valuation for Stamp Duty purposes.
The valuation will provide the correct figure on which the duty will be assessed.
Stamp duty is a tax imposed by state and territory governments on transactions such as: ... the sale and transfer of real estate, businesses and certain shares.
https://www.service.nsw.gov.au/.../calculate-stamp-duty-sale-land-or-bus...