We apparently have millionaire Cornelius Vanderbilt to thank for the “If you have to ask the price, you can’t afford it” line.

It’s one which clearly plays into the hands of restaurant owners, many of whom have their waiters run through the list of daily specials, without revealing the price, and without displaying them on a board or menu insert.

Which is illegal, in terms of the Consumer Protection Act, as it happens.

Many people are too embarrassed to ask the “what does it cost?” question, lest they come across as hard-up or stingy. Or worse: uncool. And the restaurant owners know that.

Luckily, asking awkward, uncool questions comes naturally to me, so I always make a point of asking the waiter for the price of their exuberantly described – “napped with, enrobed in” – dishes.

The point is, we shouldn’t have to ask.

So I read with huge interest a report in the UK’s Daily Mail this week about the tricks of the restaurant trade; the unpriced daily “special” being one of the main ones.

“Very often,” the Mail reported, “the special is special only because it’s the most profitable item on sale and the restaurant knows it will sell many more if the waitress singles it out for attention.”

The report was based on a new book by William Poundstone – Priceless: The Myth Of Fair Value – which focuses on how businesses exploit their customers.

Poundstone has spent years examining the psychology behind menu engineering; the subtle ways restaurants encourage us to choose the most expensive dishes on offer.

“People rarely go into restaurants knowing exactly what they want to order or how much they want to spend,” Poundstone says. “And we can be influenced by all sorts of things that we’re not aware of.”

And while Poundstone’s research was clearly UK-based, local menus appear to be following international trends, such as:

* Dropping the Rand sign. Such as a steak’s price stated simply as 78.

This is not a coincidence, Poundstone says. A study by Cornell University’s Centre For Hospitality Research in America found that when, in a similar move, dollar signs were left off a menu, sales increased by 8 percent, because the more space you devote to something on a menu, the more people pay attention to it.

So if you have a Rand symbol, plus cents, it takes up more space on the page and more space in your mental attention. “And obviously the restaurant does not want you to choose your food on the basis of price.”

* Centring the menu items on the page, rather than having the prices all lined up in a tidy column on the right-hand side.

“If all the prices appear neatly one above another,” says Poundstone, “that just invites us to compare one against the other which is the last thing the restaurant wants us to do.”

* “Anchoring” – placing an expensive dish prominently on the menu, in order to make the other dishes nearby appear relatively cheap.

* Drawing attention to the most expensive item by putting a box around it, or using a different font or colour.

The Daily Mail report quotes Professor Charles Spence, a psychologist at Oxford University and the co-author of The Perfect Meal: The Multisensory Science Of Food And Dining, as relating a recent experience he had in the London burger chain restaurant, Byron.

“The menu is all in black and white, except for one item, which is highlighted in bright red. And it’s their most expensive item.”

* Heavy menus. Spence says that people are likely to spend more if menus and especially wine lists are heavy to handle.

* Menu-speak. Flowery descriptions and words that conjure images of wholesomeness boost sales, apparently.

“There’s research that demonstrates that if you give food a more descriptive label, people will enjoy it more and they’ll also pay more for it.” Spence says.

Especially if we’ve mellowed out with a glass or two of expensive wine by the time we place our order.