First you must eat four raw shrimps from the Japanese island of Hokkaido, topped with delicately quivering sake jelly, beluga caviar and an oshishu flower. Then you will try green tea tofu and minced, highly-prized tuna belly, served tartare, and topped with a quail's egg. Follow that with platters of sushi - "modern" and "traditional" in style - and a triumphant plate of seared strips of wagyu beef served with two Japanese sauces. By the end of 10 courses you will have eaten one of London's most expensive meals, at £200 a head without water, wine or tip.

The Kyoto sushi kaiseki menu marked "market price" [it goes up to £240 depending on the ingredients available on the day] served at the über-trendy Umu restaurant in Mayfair exemplifies an increasing trend in top-end restaurants in the country's capital where diners are paying at least £100 a head for their meal. After opening in September last year and breaking records by gaining a Michelin star within four months, Umu has eclipsed Sketch, where the Lecture Room restaurant was reckoned to be the UK's most expensive dining experience, at about £450 for dinner for two.

Such high prices are noted in the the forthcoming issue of Harden's London Restaurants which says that top-end restaurants in the city are flourishing and that bills presented there have consistently risen by nearly three times the rate of inflation, having grown by 5.7% in the past year (on top of 5.6% the year before that).

It points out that restaurant bills which would once have seemed remarkable are now becoming commonplace, with Umu, Sketch, Blakes and Le Gavroche costing the average diner eating a standard dinner and drinking the cheapest wine at least £100. It says many top restaurants have "been able to hike their prices, in some cases significantly".

Yesterday's gastronomic indulgence cost the Guardian £324 for two and that was with one of the less greedy diners erring on the side of caution. The service charge was £36.

Richard Harden, co-editor of the guide, said yesterday that people reporting to Harden's "had complained about prices in London a lot as compared to eating abroad, with the exception of Paris".

But he added: "It's easy to make fun of places where people spend a couple of hundred pounds on food and people will ask 'can any food be worth that?'

"Historically, London has been quite weak on the top-end places, especially compared to Paris where, as part of its great gastronomic heritage, such restaurants have long been part of the scene. It's a measure of the emerging maturity and stature of London's restaurant market that it now offers something for everyone in every price range. There is a huge market for this sort of food among affluent young city people and it almost becomes a sort of macho thing with them where they can boast how many hundred quid they dropped at Umu or Nobu last night."

Andy Lines, food writer and manager of the foodie website egullet.com, said he didn't doubt that Harden's had the figures right but he believed that people in London have always been prepared to pay high prices for good food.

"Eleven years ago, Marco Pierre White was charging £75 when he had three [Michelin] stars," he said. "The proof in the pudding is the middle restaurants offering good value, that are full all the time like Racine and Chez Bruce, where you get good value for money. Yes, you can get ripped off in London but it isn't the only side of the story."

But the big-time prices still shock some restaurant critics. In his review of Umu, Joe Joseph, a restaurant critic with the Times, said: "The house speciality of Kyoto-style kaiseki meals comes at various price ranges. Alpine ranges, since you ask. The prices at Umu scale such peaks that they make those at other swanky London restaurants look like troughs by comparison. You can get altitude sickness just reading the prices."

And it is not just the high-end restaurants that are charging top pound, it seems. Marina O'Loughlin, food critic for the London free newspaper Metro, is often appalled at the prices being asked. She said: "Some premier league restaurants are laughably overpriced - like Cipriani with its £15 plate of tagliolini al pesto. But now even lesser joints are racking up the bills: in the space of a week I spent over £100 for two in the Epicurean Pizza Lounge. Yes, for pizza. And, in Curzon Street's Mamounia, we shelled out £10.50 for one cheesecake."

For those with a taste for finer food but without a hole in their pocket, there is a comforting new trend. Gordon Ramsay, who has his own three-star trestaurant, is also going in the opposite direction, with the opening of his new eatery, Maze, in Grosvenor Square. Guardian food critic Shaun Hill wrote on Saturday: "Maze is not expensive at about £30 a head for food, which is a snip for the most exciting new restaurant of the year."

The average price of a London restaurant meal, according to Harden's, is £36.82. And at Umu - where most of the fish is flown in from Japan along with the water used for miso soup - you can pretend to be one of the nouveau gastro riche and dine well on a set lunch menu of £22.