Ms Corbett said recent airfares were some of the cheapest she'd seen.
Low fuel prices and competition were expected to keep the fares low.
Grabaseat this week offered return flights to Los Angeles and San Francisco for $788, to Houston for $848 and to Shanghai for $798.
Air New Zealand chief executive Christopher Luxon said lower fuel costs, an expanded fleet and increased competition would pull down domestic and international prices.
Ms Corbett said travel agents didn't have access to Grabaseat deals, but those deals stimulated the market.
"[It's] very exciting for the traveller to be able to travel at that price."
An Air New Zealand spokesperson said 640 seats or 320 return trips across Los Angeles, San Francisco, Houston, Tokyo and Shanghai were made available on its Grabaseat website on Wednesday morning.
More than 200 trips had been snapped up by late Wednesday afternoon.