Hello - this is probably a relatively easy question for a local but can anyone provide a rough indication of what it would cost by taxi from Sydney Int. Airport to The Rocks.
Thanking you in advance :-)
Yes as libbyh says - you can check on http://www.taxifare.com.au/
The alternative is a train which goes from Airport to Central, change at Central for Circular Quay (station forThe Rocks) this costs about $16
Train fare is now $18.20 (a huge rip off, due to a loading for picks ups and set downs at the airport stations), but if this is an option it works well for The Rocks, as the train goes direct to Circular Quay, and The Rocks is a very short walk from there. However, this is a regular commuter train, so, during morning peak, you may struggle to get luggage on as there are no luggage racks or storage.
http://www.airportlink.com.au/trip-information/price/

If you (OP) do want to get the train, don't get a return ticket as its very expensive error.
The return is only good for a return thats up to 4am that immediate next day after your travel into the city, not a return say 7 days/14 days away.
There is a cheaper way, if you don't mind doing 2 modes of transport, and don't have a lot of baggage, that entails getting a bus (400) from Sydney International Airport to Bondi Junction, and the a train to the CBD.
Slow but cheap.
Have done it several times.

(Sydney International Airport and Sydney Domestic Airport) train stations are privately owned, profit motive is why its so expensive.
The train itself is a public transport train!
The $$$ is the "gate fee" thats charged on entry and exit to the 2 stations mentioned above.
the last time, approx 3 years ago I got a taxi from Sydney Airport to a Hotel near Central Station it cost approx $45.00. My guess to the rocks you would be looking at another $15.00 - so I'm saying it would cost around $60.