It's not easy to hold the line on prices, as any seller of French wine, Italian suits, German cars, or Spanish olives can attest. Economic conditions call for a rise in prices of European goods, but that collides with the need to remain competitive. That tension can be seen at any store that has European imports.

''We have a $10-and-under table,'' says Matt DeVriendt, manager of Smith & Vine wine store in Brooklyn. ''Some [European] wines that were $6 or $7 are now priced at $11 or $12. That makes a big difference in the volume we sell.''

Now consider a jump of that magnitude on an airplane-size scale. EADS, the parent company of Airbus, has been locked in a bruising competition with Chicago-based Boeing to sell jets to the world’s airlines.

That would be a tough enough battle under any circumstances, but it is compounded by a weak dollar interceding on Boeing’s behalf. EADS, which is cutting 10,000 jobs as part of a sweeping reorganization, recently noted that every 10-cent drop in the value of the dollar against the euro costs it an additional $1.4 billion in restructuring costs.

If the dollar is “trading at a 23 percent discount to the average currency around the world, that automatically makes our products more attractively priced,” says Sam Stovall, chief investment strategist at Standard & Poor’s Equity Research.

There is an upside to a robust currency, as inhabitants of the 13 European nations that share the euro, as well as Britons, with their strong pound, and Swedes, with their krona, have learned. They have greater buying power, and securities denominated in their currencies are more attractive to the world’s investors. The governor of the French central bank, Christian Noyer, noted that the strength of the euro proves that the currency has become “a safe haven in our globalized financial world.”

The costs of a strong euro, on the other hand, will become increasingly visible as big European companies report results over the next few weeks.

Unilever, the giant British-Dutch consumer products company, reports earnings on November 1. Europe’s largest drugmaker, GlaxoSmithKline, reports on October 23. And the giant French tiremaker, Michelin Group, reports its earnings on October 29. GlaxoSmithKline earns about half its revenue in the U.S., while Michelin Group takes in about a third of its sales there.

For many European companies, “the combination of higher interest rates and a stronger euro will combine to see [earnings per share] growth in low single digits at best,” says Ian Harnett, co-founder of the Absolute Strategy Research firm in Britain.