The Department of Fair Trading
We have information to help you buy or sell a home either at auction or by private sale.
http://www.fairtrading.nsw.gov.au/ftw/home.page
NSW Office of State Revenue – Stamp Duty Calculator
This calculator will estimate the amount of duty you need to pay on the sale or transfer of land or a business in NSW.
https://www.apps08.osr.nsw.gov.au/erevenue/calculators/landsalesimple.php