The dollar-buying spree across Europe and Asia yesterday gave Americans abroad instant relief against high prices for everything from cigarettes to bullfights and buoyed the spirits of bankers, traders and politicans.

One expert exulted that the rebound might mark the end of the worst decline of the U.S. currency since World War II.

"I'm happy," an American businessman, in Tokyo said. "We're very happy," and exporter said. A. U.S. serviceman saidhe could now think about going out again.

For the beleaguered American tourist, the price of a cup of coffee in Japan dropped from $1.40 to $1.33 overnight, a ticket to a bullfight in Spain dropped from $5.95 to $5.60, a pack of cigarettes in West Germany dipped from $1.67 to $1.53 and a dinner for four in Paris from $114 to $103.

Nobody seemed to know when the rapid climb of the U.S. currency in response to President Carter's surprise dollar-rescue plan would end. Some money dealers said it was bound to level off eventually. But for the moment, dollar fever threw markets into chaos everywhere.

"Conditions have been pretty hectic on money markets, with the dollar moving like a yo-yo." said a dealer for Barelays Bank International in London.

"The market is very, very nervous and very thin, with wide spreads between bid and offered quotes," said one London dealer.

An operator at an American bank in Paris summed up the mood: "The measures were definitely a step in the right direction, but I would still like to see some action on slowing inflation and reducing the U.S. trade deficit."

A record $1.35 billion changed hands on the Tokyo foreign exchange - nearly triple Wednesday's trading - and the dollar skyrocked from 178.8 yen to 186 yen - at 4.2 percent jump, the biggest in nearly five years.

Even the People's Bank of China in Hong Kong suspended exchange rate quotations in apparent response to the market's turbulence.

In London, the dollar gained 3 cents against the pound.

The Journal de Geneve, representing the Geneva banking community, in an article headlined "The Moment of Truth for the Dollar," said Carter "finally took the steps that everyone had been waiting for."

A spokesman for the Swiss Bank Corp. said. "This turnaround marks an end, hopefully, to the worst decline of the U.S. currency in post-war history."

Americans in Japan - including more than 40,000 military personnel and their families - also looked forward to lower prices.

"We haven't been going out as much as we used to," said an Air Force captain. "I hope the dollar will become more stabilized." He can now buy a glass of orange juice that cost $3 Wednesday for $2.87.

The dollar opened in Zurich at 1.6050 Swiss Vrancs from 1.5725, picking up anothe full point to 1.61375 during the first half hour of trading. In Frankfurt, it regained 5.375 pfennings to open at 1.89875 marks.

In Paris, reopened after the one-day All Saints Day holiday, the dollar moved to 4.28 francs from 4.0155 at Tuesday's close, while in Milan and Brussels, also closed for the holiday, it posted gains of 2.35 centimes to 30.50 Belgian francs from 28.15, and 45.45 lire to 835 lire from 789.55.

Gold again fell sharply, opening $4.73 lower in London at $222.25 and $1.25 lowe in Zurich at $219.25.