Bureau of Infrastructure, Transport and Regional Economics (BITRE) figures for December revealed the cheapest return Qantas fare available three weeks before departure was $311.

With total travel of 620 kilometres, it cost travellers about 50 cents per kilometre, more than Qantas fares to Sydney from Albury (49c), Coffs Harbour (48c) and Tamworth (39c).

The most expensive was Bundaberg to Brisbane ($517), costing 90 cents a kilometre for the 574-kilometre round trip.

Dubbo City Regional Airport operations manager Lindsay Mason said December and January were the slowest for traffic to and from Sydney.

"They are notoriously slow, most of January especially," he said.

While December figures were inflated yearly because of the busy Christmas period, Mr Mason said prices were determined by the airlines taking into account any competition.

"For Dubbo, 75 or 76 per cent of our travellers come here for business, it's a high proportion that isn't for leisure," he said.

"People also fly for medical reasons or to visit family and friends, and these (levels of travel) have all been pretty consistent."

Mr Mason admitted the prices were "a little expensive", but hoped costs would stay steady after the addition of larger Qantas aircraft.

He said the addition of Regional Express (Rex) flights had created more competitive prices in recent times.

"If you look back when Hazelton (Airlines) folded, Qantas pushed their prices right up and when Rex came in it was more a competition," he said.

"It's different now because Qantas do offer sales."

According to BITRE, Rex's cheapest fare in December was $336.80, which amounted to 54 cents per kilometre.

Qantas' flight was cheaper in comparison to that of December 2007 where travellers flew for 53 cents per kilometre, but Rex was much less on 36 cents.

In December 2005, both companies had fares that amounted to 32 cents per kilometre on a return fare to Sydney.

BITRE research revealed that for December 2012, flights nationwide stood at 95.5 per cent of their base of July 2003.