By the time he brought the gavel down two weeks ago on a record sale of American paintings—some $4.4 million worth in a single morning—John Marion, president of Sotheby Parke Bernet, could claim a career record of more than $250 million in auction sales. But even Marion, who at 45 heads the world's largest auction house, admits the current art boom astonishes him. Parke Bernet (the final "t" is pronounced), with offices all over the U.S. and Europe, now does $500,000 in business each week in this country, but that is only the tip of the art market iceberg. "Everywhere, people who used to throw old things away are bringing them to swap meets and garage sales," says Marion. "The change in the market is quite incredible." The son of retired Parke Bernet president Louis J. Marion, John earned a degree in sociology at Fordham and served in the Navy before joining his father's firm in 1960 as a salesroom assistant. A year later he took up the gavel and since then has auctioned off, among other items, the $1,050,000 diamond Richard Burton gave to Elizabeth Taylor in 1969 and Renoir's Pont des Arts to Norton Simon for $1,550,000 in 1968—the most ever paid for an Impressionist painting. In his Madison Avenue headquarters, Marion talked about the current craze for collectibles with Christopher P. Andersen of PEOPLE.

What's hot in the art market right now?

Virtually all areas of Americana—everything from grandfather clocks to paintings and prints to furniture to wooden duck decoys. Suddenly there is a tremendous thirst for the tangible in this country.

Why the collecting boom?

Over the past decade the stock market has left an awful lot of scar tissue on the average investor. So Americans are doing what Europeans have done for centuries—they're looking for an investment that is portable, beautiful, a reminder of their cultural heritage and a hedge against inflation.

Is Americana a big item on the world art market?

No. Only Americans are interested. Foreign collectors find it boring.

What are the international favorites?

It depends on the nationality. Right now the Arabs, who really aren't pumping tremendous amounts of oil money into the art market, prefer glitter—jewelry, porcelains and 19th-century gold boxes. To the Arabs, the real excitement is in the bidding itself; they consider an auction an afternoon well spent, like a game of roulette.

What about the Japanese?

They knocked the art market cuckoo in the mid-1970s, indiscriminately buying up Chinese and Japanese art, jewelry and French Impressionists. Renoir is the Japanese art buyer's favorite, followed closely by Utrillo. The Germans are also an important force because of the strength of the mark. They prefer German Expressionists like Nolde, Kirchner and Klimt.

Is there a vogue for Chinese art?

The demand has never been higher, but the Chinese are very smart. They're holding onto the tremendously valuable art objects and letting Westerners buy the comparatively mediocre stuff. Ironically, Taiwan is a far better place to look for Chinese art, because when the Nationalists left the mainland they took plenty with them.

In the U.S., has the nature of the average collector changed?

Vastly. Until maybe 10 years ago you had to be one of the 400—the very few people with real means. Nowadays the average person in the suburbs is likely to be a serious collector of something—whether it be paperweights, stamps, old bottles or antique cars.

Are there any real finds to be had at flea markets and garage sales?

At a recent swap meet held in a garage next to the Los Angeles office of Parke Bernet, we came across a Fabergé enamel box worth $5,000. People often aren't aware of what they have. One elderly woman came to us with a shopping bag full of stuff, including a big clock she thought was worth a fortune. The clock turned out to be worth about $150, but then as an afterthought she pulled a dirty old Russian enamel tankard out of her sack. We appraised it at $15,000 on the spot.

What other such surprises have you encountered?

One man came in with an old painting that had been in his family for years. It was by Brueghel the Elder, and we sold it at auction for $560,000. Another fellow read about that sale and came to us with a painting he said looked like it might have come from the school of Brueghel. It, too, turned out to be by the artist himself. It went for $410,000.

What items have increased most dramatically in value over recent years?

Art Nouveau, without question. I've watched Tiffany lamps go from $800 to $80,000 or more. Southwest Indian art has also skyrocketed. We just sold an Apache basket at $16,000. Suddenly European art from the mid-19th century is also very popular after years in eclipse—especially the Barbizon school.

What has dropped in value?

English portraiture from the 18th and early 19th centuries is now worth only 30 percent or even 10 percent of what it was in the 1920s.

What causes such a drop in value?

Changes in the collecting public's taste and a growing appreciation of other styles. Who wants to live with a gloomy old portrait?

Do you have any tips for the medium-income collector?

In the Southwest one of the hot items is Mission furniture. It is relatively inexpensive right now, but the supply is so limited that its value is bound to increase dramatically. Another smart buy is U.S. Centennial furniture—replicas of colonial pieces made specifically as part of the celebration of our 100th anniversary in 1876. A colonial highboy may fetch $50,000 today, but its Centennial replica can be had for between $1,000 and $4,000. Those Centennial pieces are in short supply, however, and it won't be long before they soar in value. Also Federal furniture made in this country between 1790 and 1815 can usually be had at a relatively reasonable price—for a collector. An armchair, for example, can be had for a few thousand dollars. That's what I collect.

What else would you recommend?

French nude bronzes can still be acquired for as low as $150. They are a superb investment. So are Currier & Ives prints or prints of works by American artists like Whistler and Winslow Homer. Autographs and historical documents are also very big now. I bought a bid slip from a Nov. 18, 1936 auction for $55. On the back it's signed "Franklin D. Roosevelt, The White House." The autographs of many famous people can be bought for well under $100.

How does a novice go about collecting?

The so-called "Three L's" of real estate are "location, location, location." The Three Q's of collecting are "quality, quality, quality." Questions you should ask before you acquire something are: Do you like it? Will demand for it grow? Did you do your research?

What do you mean by research?

You should like what you buy, but you should also learn something about it. Get in touch with other collectors and with groups that specialize in what you collect. Go to the library .and dig up books on the subject. Once you've bought something, photograph it. Then sit down and make a complete record—whom you bought it from and what you paid, its history, a description of the item. If nothing else, you'll have a record so you can claim a tax loss if it's lost or stolen.

What are your most vivid memories of the past 18 years as an auctioneer?

The big sales, of course, like the Liz Taylor diamond. The agent who bought it had a special signal: He was bidding as long as his arms were folded. I got very nervous as the price went over $1 million and his arms were still folded. Had he, I wondered, forgotten about the signal? But when the bidding was over and the diamond went to him for $1,050,000, the gentleman uncrossed his arms, and I sighed, "Thank God!" A day later Richard Burton purchased it for Liz.

What kinds of signals are routinely used?

You name it: a nod, a wink, crossed legs or arms, taking your eyeglasses off or putting them on. One customer from the Middle East said he was bidding so long as his handkerchief was showing in his breast pocket. Once he pushed it out of sight, we would know he was out of the bidding. When the price on the item he was interested in shot to $55,000, he got so excited trying to push his handkerchief out of sight that he ripped his jacket down the front.

What is the biggest mistake any collector can make?

Buying on impulse. A person who spends weeks deciding what stock to buy will plunk down $500 or $1,000 on a piece of art or an antique just because he or she likes it. That's not reason enough. On the other hand, if you're not willing to make a few mistakes, it's a mistake too—because it proves you're not adventuresome. What good is collecting if you can't have some fun along the way?