There’s a moment in the first episode of Channel 4’s new antiques show Four Rooms when everything you would traditionally expect from an antiques programme is suddenly and summarily consigned to the dustbin of history.

The set-up is familiar: a member of the public brings in an item of interest – something they bought or have been keeping in the attic – and the show’s four resident experts look it over. They include items as diverse as a nose section of Concorde, a piece of wall by the graffiti artist Banksy, a tattooed piece of skin, and in the first programme, a bust of Adolf Hitler that had been taken from a concentration camp.

From there, however, things begin to change. The show soon starts to resemble Dragons’ Den more than Antiques Roadshow. All the pieces have been brought in to be sold. The experts are all established dealers. The seller can go into any of four rooms to visit the dealer of their choice, who will make them an offer for it, even if it is only the price of their bus fare home. They can take it, haggle, or move on to the next room. They can’t go back.

In the first show, among the items brought in is a collection of Christmas cards sent by Diana, Princess of Wales to her personal chef, which the owner had purchased at auction. They begin with photos of Charles and Diana, progress to images of the royal couple with their young family and end with pictures of the Princess alone with her two sons.

There’s some discussion about the significance of the collection and the fact that the signatures on the cards are handwritten. “I can just tell you want a fortune,” says 54-year-old dealer Gordon Watson, who specialises in selling rare, “museum-quality” pieces to the ultra-wealthy.

The owner chooses to go first into the room occupied by 39-year-old Emma Hawkins, who grew up in Australia, the daughter of an antiques dealer. She specialises in exotic taxidermy and curiosities, such as deformed narwhal tusks. “No item is too weird for her,” the show claims. Not strictly true, she tells me later: “I was offered a mummified hand that was used in black magic rituals. Things like that, anything Satanic, I don’t necessarily feel I would want to touch.”

The seller turns down her offer, and before long finds himself in another of the four rooms discussing a sale with Jeff Salmon, the scarf-wearing owner of Decoratum in London, a gallery whose clients include Kate Moss, Lily Allen and Uma Thurman.

The 57-year-old self-confessed “maverick” wonders aloud “What will I pay for them?” while rolling a red dice between thumb and forefinger like a character in an Ian Fleming novel. Then he asks: “Are you a gambling man?”

Salmon proposes a deal: “If you throw odds, you’ll take ten thousand quid, if you throw evens, you’ll take £25,000.”
At that moment, given the sensitivity surrounding what they are gambling for, Antiques Roadshow suddenly seems as if it belongs to another age entirely.

“Perhaps I was feeling a little bored that day,” says Salmon, later. “It’s not the most conventional way to do business but I just wanted to mirror everything that happens in my own office.” He says the dice actually come out far more often in his everyday dealings – once a week or so.

“I’m a trained negotiator,” he says. “If I can see weakness, if I can smell blood, I’ll go for that blood. I’m like a heat-seeking missile. Just by looking at somebody, I know what somebody is thinking. My father used to say, ‘If a mug comes along, take his trousers off.’ But I would never ever take advantage... unless,” he adds with a laugh, “I really want something.”