I just wanted to give a quick recommendation for www.efragrance.com.au
I purchased a perfume (Mariah Carey's 'M') from them yesterday afternoon, and it got delivered this morning.
Not only was it quick, but they included free samples and a $15.00 voucher for next time I use the site.
I've never bought perfume online before, but they have thousands of fragrances, so it's worth taking a look!
They also have free postage until the 7th March (I think?) so it's an even sweeter deal.