People-smugglers have resorted to slashing prices and offering special deals for boatpeople seeking a new life in Australia, including children travelling for free, as the country's tough asylum-seeker policies hurt their profits, a top official said.

The number of boats arriving in Australia has dried up under the government's policy of turning them back to Indonesia and denying would-be refugees resettlement by sending them to Papua New Guinea and Nauru.

Angus Campbell, the commander of Operation Sovereign Borders, said asylum-seekers were now much less willing to undertake the dangerous journey, with people-smugglers looking at new ways to entice them.

"Prospective clients are looking for policy or operational changes before risking their lives and money on a boat to Australia. At present, the great majority have decided to wait and see," he told the Australian Strategic Policy Institute late Thursday.

In addition, many of the more affluent economic migrants who flowed into Southeast Asia looking to make the illegal trip to Australia had chosen to return home.

This had made people-smugglers more opportunistic.

"They have shown resilience and a capacity to innovate in attempts to entice new clients and circumvent current measures," Campbell said in a speech.

"Clearly the business of people-smuggling to Australia is under great pressure, with much-reduced prices, special deals, and some smugglers offering kids to travel for free: all this and more, to put people's lives at risk, in small boats on a large ocean."

Despite no boats making it to Australia so far this year, compared to a high of 48 in a single month last July, Campbell said it would be a mistake for the country to relax its guard.

"Should 50 boats a year arrive into Australia, we know from recent experience, that many more would follow," he said.

"The numbers on the move globally are so large, and the profits to be made so attractive, that both smugglers and travellers would not stop, indeed did not stop, at 50 boats."

In its budget this week, Canberra estimated its policies to prevent illegal boat arrivals would reap savings of Aus$2.5 billion (US$2.3 billion) over five years, with detention centres now being closed down.

It also announced that Aus$86.8 million would be given to Indonesia, where many of the boats originate, to help it manage its asylum-seeker population while two retired navy landing ships would be donated to Malaysia to assist its people-smuggling efforts.