A 750ml bottle of water is $2 at Countdown this week.
Massey University marketing expert Andrew Murphy said stadiums had a captive audience because of the restrictions on what people could bring in.
Punters cannot take their own food or beverages into Vector Arena. They are allowed small amounts of home-made food at Eden Park, Mt Smart and North Harbour — but not takeaways, cans, glass bottles or drink containers bigger than one litre.
"It's another way the stadium authorities can recoup their costs," he said. "You eat all these chips and salty food, what do you want? Beer or water."
At all the venues, hot chips cost about twice as much as at a randomly chosen Auckland takeaway outlet, and a hot dog two-and-a-half times as much.
Auckland woman Michelle Curran says it is annoying to be charged $9 or $10 for a glass of wine after she had spent a lot of money on tickets to an event. "And you line up forever."
Vector will sell a Heineken for $9 but guest imported beers can be $14. At North Harbour stadium, wine is $9 a pop. The quality of that wine will vary. In corporate boxes and lounges, the same $9 buys a smaller glass but better quality. Retail, it's $9 for an entry-level bottle of wine.
Shaun Wijnstock, operations manager of North Harbour Stadium, says catering can be an "absolute nightmare".
"You never know how many people you will have through the gates.
"Sometimes only a small amount will turn up. That's why there's a premium on food. You have to cover the cost of the staff serving."
A crowd of 25,000 would require up to 25 staff per retail outlet.
Eden Park has some of the cheaper prices, but fans still aren't happy. A 600ml soft drink there is $4.50, compared to $3.99 at Countdown, and burgers cost up to $9.50, about the same as the most expensive Wendy's burger.
An Eden Park spokesman said there was no premium added to its prices. "We want to make sure it is affordable to visit the stadium and enjoy something to eat and drink while you watch a game with your family."
But, on the stadium's Facebook page, Bill Keesing disagreed: "Eighteen dollars for a lamb burger, chips and a drink? The phrase 'utter rip-off' springs to mind! I certainly won't be buying food here again."
Tua Numanga posted that he had paid $8 each for stubbies of beer at the Nines. "I bought a 12-pack of Wild Buck beers from a wholesale for $17.99. You people charge $8 a stubbie."
Parik Kansara wrote that the stadium was a "rip-off for alcoholic beverages".
The Eden Park spokesman said the stadium used historical product data and ticketing information to forecast what would sell. The most popular items at a rugby match were always soft drinks and hot chips.
Sports fan Mike Heard said the fact that alcoholic drinks were expensive at stadiums was sometimes a good thing. "I believe it was because of this that people were well behaved [at the Nines]. What I don't agree with is the non-alcoholic drink being highway robbery and the food being unaffordable."
He said he had noticed water in particular being over-priced.
