"It was a great way to generate immediate interest and we had a lot of enquiries. We are now in talks with a person who doesn't want the car but is prepared to negotiate over the price of the house instead, so our strategy seems to have worked."
Another rising trend is vendors offering high-end properties for sale with "all trades considered".
Auckland real estate company Precision has two such mansions on the market, in Coatesville and Waitoki. They each have price tags of $4 million-plus but owners are prepared to consider trading properties.
"It is very rare that homes in this range would end up becoming a straight swap for a house of similar value," said Precision agent Suzie Eade. "It's more likely that someone with a property valued at say, $2 million, will offer that in exchange along with a cash balance.
"That way the vendor realises some money and also inherits a $2 million house that would be much easier to flick on than something priced at $5 million."
Eade said she had seen a recent rise in people offering vehicles, boats, diamond rings and even horses to clinch a deal.
"I have two properties with boats worth more than $1 million being added to the mix to encourage a deal. Sometimes you have to think well outside the box to get a sale over the line."
However, Grant Parker, veteran sales consultant at Harcourts on Auckland's North Shore, still believed the best way to flog a property was through an agent.
"People try to sell houses themselves by chucking in sweeteners as a negotiating tool, and good luck to them," he said. "But selling a house is much harder work than most folk think."
