Hi
To answer your Question on buyiny cigarettes before you arive in Australia it will be alot cheaper duty free then in shops here but be aware that you can only bring in so many packets they should be able to tell how many at the duty free shop
In australia now you are not alowed to smoke in any hotel or eating places and alot of other places you have to go out side to smoke also.

All big australian airports also have duty free shops in the building where you can buy before you go through customs after you arrive. There are also duty free shops in the cities and shopping centres where you can buy your duty free before going to the airport - you either take the goods home sealed with a tag for customs to collect when you leave or you pick them up at the duty free shop or a kiosk in the airport. Dont be tempted to open any duty free ( if you buy pre airport when your leaving) to give to someone or use before you depart if customs see the bag has been tampered with you may end up with your stuff confiscated + a fine. ( the bags are very well sealed with tags hard to fiddle with!!!)

cigs arent cheap in oz but remember when you are looking at prices that cigs over there are ( if still the same) sold in packs of 30 to 40 rather than the 20's you get here.