Los Angeles options trader Marcus Adler relishes a good after-dinner drink, and with a $500,000-plus annual income, he can easily afford to pay for a fine one. But during a recent trip to the Big Apple, he balked at the price of one that really intrigued him – a 1.5-ounce shot of vintage cognac at $800, which is said to be the single most expensive after-dinner drink on the New York City restaurant scene.

“I love cognac,” he said, “but I can’t imagine paying more for an after-dinner drink than I do for my flight to New York or my hotel room.”

Surprisingly, the drink is not being offered at such pricey dining delights as Per Se, Jean Georges, Daniel, or Alain Ducasse, but at Tse Yang, an upscale, 13-year-old Chinese restaurant at 34 E. 51st St.

If you’re about to say the $800 price tag is ludicrous, that no one, not even the deep-pockets crowd, will plunk down that kind of money, you’re wrong. Tse Yang’s general manager, Alan Chan, said the restaurant has actually ordered a second bottle of the cognac (an 1863 Hardy Perfection from the Cognac region of France) after its customers consumed the first one.

Besides Mr. Adler, Another Tse Yang diner, Chicago public-relations executive Martin Janis, also took a pass. Mr. Janis, who was at the restaurant with the head of a biotech company, quipped: “I’m sure the cognac is the biggest bargain in New York, but how can I pay for a drink that exceeds the earnings of a client?”

For Tse Yang – which is near the Helmsley Palace Hotel off Madison Avenue and does a sizable business with Wall Street and international clientele – sales of this pricey cognac, even on a minor scale,are proving to be scrumptious.

The 1863 bottle, Mr. Chan said, cost the restaurant a little over $4,000 and contains 14 shots. At $800 a shot, Tse Yang realizes total sales from the bottle, before taxes, of $11,200. That’s a grand profit of $7,200 or 180% – a profit of $515 for each drink served. So far, the restaurant has sold six drinks from its second bottle of 1863 Hardy. All told, only 300 bottles of the 1863 cognac were ever produced.

For customers who want something older, the restaurant also offers a single vintage 1806 Ferrand cognac for $800 a glass. The bottle – only 60 were produced – cost the restaurant $3,800. So far, it has sold two drinks.

“We’re never going to get rich on these drinks,” observes Mr. Chan, who views the two rare cognacs as primarily prestige items. Everyone, he notes, complains $800 is way too much, but some are curious and order it anyway. He adds there has never been a complaint; the customers all seem to love them. Mr. Chan acknowledges that Tse Yang, where the average dinner check runs $70 a person, will never do a huge business in either of the pricey cognacs. But he contends it’s worth offering them because they’re talking points and add to the allure of the restaurant.

With the average after-dinner drink in the city running $15 to $20, Tse Yang’s two $800 cognacs, several restaurateurs tell me, surpass anything in sight by a huge margin. “Like the spaceship, those drinks are in outer space,” said a captain at the Four Seasons, whose two most expensive after dinner delights, both cognacs, are a Martel d’Or at $250 and a Remy Martin Louis XIII at $150. Jean Georges has a 100-year-old Drillet Century cognac available for $250 a shot.

By and large, fancier after-dinner drinks – which include Chateau d’Yquem, the darling of sauterne lovers, vintage ports, Louis XIII, and Bas Armagnac – generally range from $85 to $150. At most of the city’s finer restaurants, Louis XIII cognac (stored in a Baccarat crystal bottle) is the highest priced after-dinner drink.

Who, you might wonder, would shell out $800 for a shot of cognac? Mr. Chan wouldn’t identify any of the customers, one of whom frequently orders the cognacs. He would only describe them as well-to-do businessmen. Since he sampled the two cognacs, I asked if he though they were worth the ritzy price. Describing both as very smooth (let’s hope so), his answer was an emphatic yes, with the proviso “but only if you want the very best and you can afford the very best.”