The ACL as per the ACCC site just says " You do not have to return products in the original packaging in order to get a refund" in regards to packaging requirements.
The cost of properly packaging and posting the item back are also claimable as long as the costs are reasonable for the type of item and it is confirmed the item was faulty “You are entitled to recover reasonable postage or transportation costs from the business if the product is confirmed to have a problem, so keep your receipts”.
When the item is large the business is responsible for transporting the item but a consumer needs to keep in mind that the business can recover the costs if the item is not faulty but they should provide you an estimate before the goods are collected by them “If the product is found not to have a problem, you may be required to pay the transport or inspection costs. An estimate of these costs should be provided to you before the product is collected, and the costs must not be inflated in an attempt to deter you from pursuing your claims”.
If buying direct from the manufacturer the ACCC has this to say:
"Goods bought directly from the manufacturer
Manufacturers and importers act as suppliers when they sell goods directly to consumers and have the same responsibilities under the consumer guarantees.
What if the manufacturer fails to honour an express warranty?
If the manufacturer refuses to honour an express warranty or fails to do so within a reasonable time, the consumer can take legal action to enforce the warranty in a tribunal or court.
The consumer can also:
• assert their rights under the consumer guarantees
• ask for compensation for consequential loss due to the manufacturer’s failure to meet the warranty
What if there is no express warranty?
If there is no express warranty and the manufacturer has not met a consumer guarantee, the consumer can assert their rights under the consumer guarantees."
That is the manufacturer is treated exactly the same as a retailer in these cases.