This law is a bit of a crock. Like the article says, a lot of REs have been self regulating on dummy bids for a while now. I often hear the RE say, "I'm submitting a bid on behalf of the vendor for $xxx thousand".
It'll be perfictly legal under the new laws, regardless of the if the price is realistic or not. I've seen agents do this and then pass the property in with no further bidding. The newspaper on Monday states the property was passed in at $xxx thousand. Then along comes someone who wasn't at the auction, but knows wat the passed in value was, so they make an offer 5k higher and buy the property. It doesn't matter that the last bid at the auction from a real buyer was $40k less, it's still legal.
As for the impelmentation of quoting a price range before auction, this is almost completly unenforcable. At the end of the day, the agent can just say that they didn't expect the result to be 25% higher than they quoted, but the vendor is delighted with the result.
If they want to legislate on this issue, perhaps it if a reserve is set before the auction, it should be made public. If the reserve has not be set, the agent should be legally required to reply that it has not been set.
Legislating on these issues is of little protection to the consumer. The best protection is to know what you're willing to pay for the property before hand, and negotiate/bid with that figure in mind.