A New York investment banker, Hugo Heath, says he hasn't recovered yet from his flight from Amsterdam to Copenhagen last month.

While the flight wasn't extraordinary, the price tag certainly was.Heath paid $700 round trip for the one-hour flight - $150 more than his discount round-trip ticket from the United States to Europe.

"It was totally outrageous," he said. "But I was trapped."

While bargain-basement air fares from the United States to Europe have been plentiful for years, fares on the Continent can be more expensive than a suite at the George V.

With airlines shielded from competition by trade agreements that assure virtual monopolies on many routes, European carriers have been free to charge exorbitant fares.

But all of that may change soon.

Industry analysts and consumer groups are optimistic that as trade barriers collapse in Europe in 1992, air fares will fall as well, as airlines slug it out in fare wars like those spawned by deregulation in the United States in 1978 (although the European battles will probably be less brutal).

Indeed, cracks are already beginning to appear in the wall.

Flights between some cities, like London and Amsterdam, are already virtually deregulated, and, predictably, fares on those routes are lower than elsewhere in Europe.

New airlines are cropping up, and carriers are flying to smaller cities and less crowded airports, not just the traditional gateways like London and Paris.

"There is certainly a more competitive spirit than there was a few years back," said John Parr, head of Britain's Air Transport Users Committee, a consumer organization based in London.

"You have a wide range of fares, increased choice of service and a lot of better deals for people who shop around for them," said Geoffrey Lipman, managing partner of Global Aviation, a consulting firm based in Washington.

Still, fares on many routes remain high. And the consumer bonanza predicted by some advocates of Europe 1992 may not fully materialize.

And since airlines pay more for fuel, labor and air-traffic control in Europe, the peanut fares that delighted consumers in the United States in the early 1980s, will probably never take hold on the Continent.

That said, there are still many ways for the savvy consumer to find bargains before 1992.

Many of the cheapest fares between European cities are available only in Europe, so it often makes sense to buy your ticket overseas. At least one travel agent, DMS Travel in New York, offers some clients a refund on tickets purchased in the United States if they find a better deal overseas.

London, Amsterdam and Athens are the best cities in which to find discount fares within Europe. In particular, London has the most bucket shops, or low-overhead ticket consolidators, and Margaret Thatcher's free-market politics has nurtured a For instance, Air Europe, until recently a small charter airline, is now Britain's second-largest international carrier behind British Airways, with 300 flights a week. The airline calls itself "the first truly pan-European airline."

Unburdened by the high operating costs of the industry giants, the spunky carrier is able to offer lower fares.

In what many see as a model for Europe 1992, Britain and the Netherlands signed an agreement in 1985 that allows airlines serving the two countries to fly when they want and charge whatever fare they like. Similar agreements were drawn up for flights from Britain to Ireland and Belgium.

"There is little incentive to reduce fares if there is no competition," said Alex McWhirter, an editor at Business Traveler, a London-based publication.

"It takes another airline to ruffle the feathers of the big boys."

The conversion of prices to dollar amounts was made in the last week of September, but fares are still likely to change because of currency fluctuations.

Slade Travel, based in London, uses what it calls creative pricing to offer low intra-European fares. Like ticket consolidators in this country, Slade buys large quantities of seats on airlines and sells them to consumers at substantial discounts.

In fact, some of the agency's fares are below the lowest published economy excursion tickets.

Often, the tickets are sold on non-European airlines. For example, Slade offers flights from London to Paris on Air-India for about $130, provided the tickets are purchased two weeks in advance. Other destinations include Amsterdam ($135), Cairo ($390), Madrid ($165) and Geneva ($135.)

(Slade Travel can be reached from the United States by dialing 011-44-81-202-0111 or by writing to 417 Hendon Way, Hendon, London NW4 3LH, England.)

Keep in mind that tickets bought through bucket shops are usually nonrefundable and may carry length-of-stay or day-of-week restrictions. In addition, although Slade does accept credit cards, some bucket shops do not.

Charter flights are another way to save money. While most fares within Europe are still government regulated, the charter business is immune from such restrictions and now accounts for about half of the air traffic within Europe.

Sometimes, the best way to save on air fares in Europe is to take the train.

Europe has a vast rail network, so it may make sense to fly to a major city, then take a train to your final destination. For instance, if you are traveling from London to Pisa, it is cheaper to fly to Rome - a fairly competitive air route - and then take a two-and-a-half-hour train ride to Pisa. The saving over the $262 cost of flying directly to Pisa is about $52 for first-class train travel from Rome, $63 for second class.

In addition, many travel agents recommend buying an open-jaw ticket.

An example would be a ticket from New York to London, with a return flight to New York from Paris. The customer could then fill the open London-to-Paris leg with a discount ticket purchased in Europe.

Meanhwile, with a free-market Europe still more than a year away, some airlines are already undercutting their competition on some regulated routes. The regulators, it seems, are looking the other way.

"It isn't easy for the authorities to act as a wet blanket," said Vagn Soerenson, marketing chief in Europe for Scandinavian Airlines. "Everybody is already mentally prepared for the coming single market."