If a store has a good sale price on an item and it sells out before you get there, that's generally tough luck. But if a store advertises an item and never stocks it in the first place, it can be fined for deceptive practices. The ACCC just demonstrated that by issuing infringement notices six WA Harvey Norman franchisees for advertising a Kodak camera in a print catalogue but then never stocking it.
The ACCC fined the six franchisees because the practice of advertising an item that can't be purchased is classified as "bait and switch" behaviour. ACCC Graeme Samuel used the ruling to remind consumer of their rights:
Promotional material must be accurate and there must be adequate stock of the advertised product to meet reasonable demand, otherwise businesses risk bait advertising which is illegal.
This kind of ruling is why you'll often see small print in catalogues from major chain stores specifying which items are not on sale in certain stores, and why stores often specify quite precisely how many of a given item will be on sale. (It also reminds us that, oddly, individual Harvey Norman stores are not owned by a single franchisee -- the computer department is often owned by a different person to the furniture section, for instance.)