A Snickers bar and a bottle of Gatorade were rung up at a combined $24 on Tuesday at a concession stand inside a large convention center, after which the customer declined to buy them and the cashier, according to both parties, laughed.

The customer, who had approached the counter with the two items and a card already out, was told the Snickers came to $14 and the Gatorade to $10. He asked whether there had been a mistake. The cashier said there had not. He asked whether the Snickers was made of anything unusual. The cashier said it was a Snickers.

A spokesperson for the facility said the pricing reflected the building’s exclusive food and beverage arrangement, under which no other Snickers may enter the premises. “The customer is free to bring his own,” the spokesperson said, “except that he is not.” The spokesperson added that the figure did not include the service charge, which had not yet been applied and which the cashier said she would have gotten to.

Asked to explain the number, nearly everyone nearby offered the same two words. “That’s just Las Vegas pricing,” said a man waiting behind the customer, who was holding a $9 bottle of water and did not appear to be questioning it. The phrase has been adopted by the facility, its vendors, and several attendees as a complete explanation, and it has not been challenged since approximately 1996.

The rest of the menu

The Snickers and the Gatorade were not outliers. According to the board behind the counter, a pretzel was $16, a small coffee was $11, a bag of chips was $9, and a banana, described on the board as “fresh,” was $7. A sandwich was priced at $28 and came with a second, smaller sandwich, which the cashier said was “for the table.” No one at the stand could say which table.

The facility said all prices were set in good faith and reflected the cost of doing business inside a building that is, in the spokesperson’s words, “very large.”

Where the $24 goes

The price is explained in part by the fact that no one in the transaction is the only one getting paid. The company that holds the exclusive food and beverage contract pays the facility for the right to be the only seller, and that payment is recovered at the register. The company that holds the contract has a parent company, which also expects a return. The brand that makes the Snickers is paid. The brand that makes the Gatorade is paid, and in some cases pays the facility for the right to be the only sports drink in the building. The company that manages the stand is paid. The company that supplies the cooler is paid. The person who ran the numbers that produced $14 is paid, and a different person approved the numbers, and that person is paid too.

According to a person familiar with the arrangement, who asked not to be named because they were not sure whether they were allowed to describe it, “everyone gets a cut, and the cut is calculated on the price, so nobody has ever asked for the price to go down.” The person added that this was not a conspiracy but a structure, and that structures do not need anyone’s permission.

The ending

The customer set both items on the counter and said he would pass. The cashier, who had been standing very still, laughed first. The customer laughed second. The two then stood laughing together for what witnesses described as an unusually long time, long enough that the line behind them stopped checking its phones. Neither mentioned the price again.

The Snickers and the Gatorade were returned to the shelf, where, at press time, they remained available for $24.