Australian Online Supplies

For dry goods they look excellent (without converting USD to AUD.)

Live stock is a bigger and very important question. As always, your best bet is to find a local auarium club closest to your area and pay the minimal due's and attend some meetings! You should be able to call the breeder of your bag of fish if you get stock from a club meeting auction.

Otherwise, you must judge the business as any other.

IME, wetgoods must come from reliable and totally trusted sources. Don't bid on words, but be there to view the bags prior to bidding.
 
I have brought wet and dry goods from them, there prices are reasonable and the plants are in excellent condition when they arrive.
 
AquariaCentral.com