There have been a number of stories published recently about price drops for top end properties, where vendors sold for less than for what they paid. If it is a first resale of an apartment (or a new house in a development), the vendor may not have actually paid what the government records say, and may not have actually suffered a loss.
For new apartments, the original off-the-plan purchaser is sometimes given an incentive from the developer. The developer does not want to drop the sales price, because the developer wants to be able to report to past and future buyers that the prices are steady or going up -- when if fact they are not. So the sales price is written on the contract and reported to the Dept of Natural Resources as the sales price, but in fact the buyer is actually paying less.
This is clearly illegal. (Read this legal decision, paragraphs 14 and 15, if you do not agree.) The developer, purchaser, real estate agent and solicitors involved are all breaking the law doing this.
Sometimes the rebate is given as a straight cash refund at settlement. For example, here is text from a "contract instruction sheet" prepared by a Juniper agent for an apartment sale in Queensland, giving instructions to the lawyer to prepare the contract of sale (the purchaser did not end up going ahead):
"The Purchaser to receive a rebate of $500,000 at settlement of Contract"
Another way to do a similar thing is by way of a rental guarantee. I was offered a rental guarantee on an apartment, and was told that money could be paid to be as a cash payment at settlement to cancel the rental guarantee.
A third way to do this (and it is not clear whether this is illegal or not -- but it is dubious) is where the developer pays rates, body corporate or adds a furniture package "for free". For example, I have seen apartments offered for sale at $515,000 with the developer paying body corporate and rates for two years. The contract price will show $515,000, and assuming that rates and body corporate are $5,000 a year, then the purchaser is in effect only paying $505,000. But the records will show the sale as being $515,000.
So take care when buying from the first owner of an apartment or spec house -- the price in the records may not actually be the price that was paid by that owner.