I feel that Asian liquor prices are a bit better than SYD at the moment. Certainly LAXs pathetic excuse for a Duty Free shop had Laphroaig at USD35 (IIRC). That made it cheaper than the AUD56 (or was it 59) in SYD. At the end of the day, I reckon its safer getting at home as there is less problem with credit cards and less to carry (and less to fall on your head "in case luggage has moved in flight").
As for cancer enhancers, no idea (no offence intended!).