These include groceries, household goods, electrical goods, but not certain living costs such as car purchases, school fees and utilities which are usually covered by separate allowances.
"Living costs for assignees are affected by inflation, availability of goods and exchange rates, all of which can have a significant impact on assignee remuneration packages," it said.
Wellington is ranked 19th in the region and 39th most expensive globally, and Christchurch is 24th and 51st respectively.
Karachi, Pakistan, is the cheapest location surveyed in Asia Pacific.
A spokesman for Auckland Mayor Len Brown said the survey came at a time of "unprecedented immigration" including expats returning home, and given those pressures, the higher ranking was "perhaps not surprising".
"It's interesting to note the cost of living for expats in Auckland remains lower than that of Australian cities such as Sydney and Canberra, other international cities we compete for skilled migrants such as Singapore and Hong Kong and other cities that rate highly in the most liveable city stakes such as Zurich and Copenhagen," the spokesman said.
Expat banker Eric Chuah said he noticed how some things were more expensive in Auckland when he first arrived here in August last year.
Mr Chuah, 35, ANZ's head of international and migrant banking, has worked in several international cities including Melbourne, Brisbane, Beijing, Taiwan and Singapore.
"I came here for the culture, the work-life culture here is fantastic and there's balance, and the Kiwi 'can do' attitude are some of what attracted me here," said Mr Chuah, originally from Malaysia.
"You have clean air, great education for the kids, it's those non-financial stuff that needs to also be taken into consideration."
Mr Chuah, who gets paid in New Zealand dollars, said the high Kiwi dollar has also worked to his advantage.
"I have investment in other countries so the high Kiwi works in my favour, and because I travel quite a bit it, the high dollar also helps," he said.
Shanghai and Beijing, the 3rd and 4th most expensive locations in the region, are also both in the top 15 globally.
"Despite slower growth in China, the price of items in ECA's shopping basket rose faster this year than last and Chinese locations continue to rise in the ranking," said Anna Michielsen, general manager Australia, New Zealand and Pacific.
"As the imported goods and brands expatriates are familiar with become more readily available, particularly in the second tier cities, this is also contributing to price rises."
For the second year running, Caracas in Venezuela is ranked as the world's most expensive city for expatriates.
Most expensive cities for expatriates
1.
Caracas, Venezuela (2013 rank 1)
2.
Luanda, Angola (2)
3.
Oslo, Norway (3)
10.
Seoul, Korea (22)
12.
Tokyo, Japan (10)
14.
Shanghai, China (19)
26.
Singapore (31)
29.
Sydney, Australia (32)
34.
Canberra, Australia (41)
36.
Auckland, New Zealand (54)
39.
Melbourne, Australia (47)
42.
Perth, Australia (49)
43.
Wellington, New Zealand (62)
45.
Adelaide (48)
48.
Brisbane (56)
51.
Christchurch
- (source: ECA International)