A Maryland collector spotted a Samuel Kirk silver coffeepot at a New England flea market, recognizing the unique Baltimore hallmark. The collector bought the coffeepot, worth about $1,000 for less than $50.

And then there was the pewter collector who discovered a black "ash try" at a flea market and bought it for $5. After cleaning, a rare touchmark on the underside of the handle became visible and he knew he had an 18th-century porringer worth hundreds of dollars.

A New England school teacher found a folk-art painting for $6. Research proved it to be the work of the Shutes (a husband and wife painting team), and it was later sold at auction for $22,000.

Susan Wasserstein, author of the recently published "Collectors' Guide to U.S. Auctions & Flea Markets," has many such tales to tell about diamonds in the rough -- treasurers unearthered at bargain prices. (She compares the rummager at auctions and flea markets to an archeologist.)

Wasserstein hears stories like these wherever she goes, and she gets around a lot. Hers is the only book listing auctions and flea markets from coast to coast. Intended especially for use by the traveling colelctor, the guide had been divided into six geographical regions, with introductory profiles of each.

Wasserstein writes tha the mid-Atlantic states have more antique auctions and flea markets than any other area of the country, and she says that the Philadelphia-Baltimore-Washington-Richmond corridor is the richest source in the United States for American folk art. The painted futniture, grandfather clocks, frakturs (illustrated documents), samplers, quilts, pewter, tin and ironware of this region are among the hottest collectables going.

Auctions and markets are organized alphabetically by state, city and town. Specific information -- business hours, frequency of sales, house specialities and whether there are restrooms, parking and motels nearby -- is given about each.

A Washington colelctor, for example, can imagine how handy it would be to have such a guide in the car glove compartment for a trip through Pennsylvania Dutch country. While not every auction and market is listed there are enough to give anyone a good start.

Wasserstein attributes the recent tremendous upsurge of collecting fever in America to three main factors: a nostalgia craze brought about by the worrisome times we live in ("the good old days"); a desperate attempt to hedge against inflation by investing in tangibles; and an overwhelming yen for the fine craftsmanmship of the past. She gives examples of old, relatively inexpensive kitchen implements which work better than their modern counterparts: certain biscuit cutters, juicers, nutmeg graters, potato mashers and the like. She feels the same is true of many carpentry and farm tools, and, of course, clocks and furniture as well.

Wasserstein doesn't like to try to predict what's coming up, what's cheap now and is surely going to appreciate, because she thinks you should forget about that aspect and buy things you really like and enjoy. That way you can't possibly get burned and, if your purchases turn out to increase in value, that's pure gravy.

But, when pressed, she does say that all Victoriana (1837-1901) is still relatively cheap and sure to go up in price. Much Victoriana is considered "collectable" and not antique. (Strictly speaking, antiques, of course, must be over 100 years old.) She advises buying any of the oddities and bric-a-brac that appeal to you, and adds that a late Victorian silver tea set for example, with its great charm and craftsmanship, may cost less than many contemporary sets.

She also can't understand why handsome continental silver (ususally 800 parts silver, the European standard) is still quite inexpensive. And she adds that old bank notes, with their fineengravings (scripopholy), are just beginning to attract attention. Some of the beautifully carved netsuke (Japanese kimono toggles are not expensive and are well worth colelcting.

But she says in every case buy the best you can possibly afford -- the real thing, not a reproduction, even if it has to be a small object. To do this you may have to acquire some expertise, and she advises talking to dealers, visiting museums, and reading books and journals on the subject. Museums, antique shows and restoration projects are mentioned all through the guide and a list of periodicals of interest to collectors is given at the end.