eBay AU will be allowing sellers to offer their buyers the ability to submit a "Best Offer" on Fixed Price and Classified Ad formats.  eBay research shows that eBay US sellers average a 10% increase in sales when offering buyers the opportunity to submit a best choice (or Best Offer in the US).
 
This new feature will be available in early November.  You can read the Best Offer FAQ's here:
 
 
Here is the announcement:
 
From early November, Best Offer will be available across all categories on eBay.com.au for items listed in fixed price or classified ad format.

Currently only available within eBay Motors in Australia, Best Offer is a great way for buyers to get an item they want at a price they are willing to pay and an excellent opportunity for sellers to increase the likelihood of a sale. In fact, our data shows that sellers using Best Offer on eBay.com have seen an average 10% increase* in conversion rates.

Best of all – Best Offer is a free feature so find out more about how to use it now so you can be ready to take advantage when it launches next month!

We wanted to get Best Offer out to you before the Christmas rush but we should point out that it won’t be supported by Turbo Lister or most third party listing tools until next year. In the meantime, you can still take advantage using the Sell Your Item form, Selling Manager or Selling Manager Pro.

Regards
The eBay team