So, with that said, on page 5 of this booklet, I found the wording to be a little bit unclear. All's I will say is I have researched it and my findings are as follows (always chat to your solicitor though before you sign the agreement - please):
The wording in the REAA booklet reads that you pay your deposit on Acceptance and the commission is then paid to the Agents when the contract goes Unconditional. Let me start by saying, you DO NOT have to pay a deposit on the Acceptance of the Sale & Purchase Agreement. In my opinion, I would advise you to pay the deposit on the Unconditional day, you can even hold the whole amount and pay all of it on Settlement day if you really wanted to (might be a bit tougher to get the Vendor to agree to that though).
Please keep in mind that you as the buyer can be in just as much control as the vendor, you can negotiate the terms of sale too. So for example, if you only want to pay $10,000 as your deposit on Unconditional day and the rest on Settlement day, as long as the vendor agrees, then you can do that. This example is common, especially when you have a smaller deposit to start with.
If you have comments to add, please do, be good to get the feedback on this issue.
Right, now I can sleep easy.
;-)