Shopping at a store -- that's a sure bet. Everything has its price, clearly marked.

Shopping at an auction -- now that's a gamble. Nothing has a price, except what the market will bear.

Have a problem with self-control? Beware of auctions. They can be a bad trip to the kingdom of impulse buying, where a 30-second bidding war can shatter even a smart shopper's record of self-restraint.

Go in search of a set of juice glasses for $20, tops. Come home with a $385 roll-top desk too massive for the one-bedroom apartment -- which doesn't matter so much, really, because no way that monster is going to fit in the Saturn to take it home, anyway.

On the other hand, at an auction you just might live out the American dream of getting something for (almost) nothing; say, a '70s Barbie for $8 that is the spitting image of one you saw for sale at an antiques shop for $165.

Like your merchandise pristine and guaranteed? Better stick to the stores. Auctions can be down and dirty.

Whether it's furniture or fine art, antiques or autos, horses or housewares, auction "lots" usually are sold on the "as-is" buyer-beware principle. They may be damaged or incomplete or more or less than what they appear to be. Some items even seem doomed to perpetual travel on a mercantile version of the Mobius strip, from owner to yard sale to flea market to antiques shop to auction and back home again, usually the worse for wear.

Shopping at a store can be so impersonal. Buying at an auction is anything but. At auctions, people weigh heavily into the equation, and that doesn't mean just the auctioneers, with their speed-tongue "chants" and their corny, crowd-pleasing jokes.

For example, what's the story on that trio of men, sleek as otters in their skinny leather coats and slicked-back hair? They are in constant consultation on their cell phones and seem to be buying by the pallet-load. It's tempting to trail them outside to see if their car matches their couture.

And that furniture dealer who spent 10 minutes pawing the claw-foot chair with the missing digits, turning it upside down to peer intently at the furniture maker's mark? The chair looked like a piece of junk, but she apparently knows something you don't.

More to the point, who is that jerk who persists in topping your every bid by a measly few bucks?

Then there are the people who don't attend the auction. They are a presence too.

What romance was behind the "Jimmy, you made my life possible" inscribed on the flyleaf of a 19th-century book of Shakespearean sonnets? And what bad thing possibly could have happened to that '40s family that their album of yellowing photographs of beach vacations and birthday parties would end up for sale to the highest bidder?

Rummage through the worldly goods of a stranger's life, and your hands can come away coated with unknown memories, a patina of past lives not available off the rack at Macy's.

Every odd attraction of an auction is taken to its extreme on a soggy winter Saturday inside a dank warehouse in a dreary industrial area just off the Beltway near Alexandria's Landmark Plaza.

About 50 people have abandoned their cozy weekend beds to arrive at the warehouse by 8 a.m. The lure is a storage auction to be held at 10, and for two hours beforehand, people can "preview," or look over, the merchandise.

Ron Beavers of Mount Vernon Auction Center in Alexandria is in charge of the sale, and he explains that over the years, a moving company had -- shock, shock -- misplaced some of its clients' possessions. Insurance companies long ago paid off the claims, but at some point, the lost items resurfaced and were stored here. The mover recently was bought out, so the warehouse contents, some of which appeared to have been untouched since the '50s, are to be auctioned.

"Appeared" is the operative word at this auction. Although garden furniture and office chairs and bookcases -- some tacky, some top-of-the-line -- are in plain view, much of the material that is going on the block is secreted inside sealed boxes, the contents to be bought sight unseen.

Oh, the boxes may be labeled "dishes," "sheets" or "dining room," but moving boxes tend to get reused, and no one knows for sure what actually is inside them.

"You're buying a pig in a poke," says auctioneer Fred Reger cheerfully. He then relates a tale he's obviously told before about boxes marked "temple urns" that drew a frenzy of bidding at one auction he worked. People were imagining treasures of the East, but what the winning bidders got were garden-variety pots that happened to have once belonged to someone named, yes, Temple.

Reger, one of about 1,600 auctioneers licensed and bonded in Virginia (Maryland and the District don't require licenses), today is alternating the selling job with Derek Hopkins. The two men will take turns "walkin' the line," meaning that instead of standing on a platform and having the merchandise brought to them, they will move from lot to lot through the warehouse, doing their sing-song sales spiel as the bidders and kibitzers trail along behind. Bidders are advised to "hug close" or risk buying the wrong box. Because boxes look a lot alike, some people carry spray cans of paint to mark their prizes.

Reger estimates that most of the boxes today will go for between $20 and $30. He recommends looking for clues to a given box's contents in the unboxed objects displayed in its neighborhood.

For example, the heavy boxes beside the huge oak entertainment center are a good bet to contain records and tapes as labeled -- that is, if they came from the same lot as the entertainment center, which is likely, but definitely not definite.

"That one," Reger says, pointing to a locked trunk marked "Africa," which has been attracting a lot of lookers, is "pregnant with potential."

His advice: "Look first, and cross your fingers."

And "never get carried away with your spending," he warns, before adding with a chuckle, "unless the auctioneers want you to."

"It's the biggest crapshoot in town," says Mark Brown happily as he does a tilt test to assess the weight of a battered box. Too light, probably a lampshade. Forget it.

The Woodbridge resident goes to storage auctions all the time. He has paid $40 for a box that turned out to be filled with $800 in silk bedspreads and curtains and $400 in vintage clothing. But he also has paid $15 to $25 a pop for a bunch of boxes filled with outdated sixth-grade geography texts -- fodder for the landfill.

Brown, who has a sideline buying and selling antiques, has come loaded for bear today -- his empty trailer is parked in the loading bay, and he hopes to take it home filled. Brown, like some other veterans of storage auctions, has had the foresight to bring a flashlight to aid in his examination of the boxes because the warehouse's fluorescents are so far overhead that they aren't very illuminating.

"Dusty is good," Brown explains as he looks over a "china barrel" or "dish pack," terms used for heavier boxes that usually protect more fragile -- read, valuable -- items. The presence of dust indicates not only age -- and old is generally considered better than new at storage auctions -- but that the container hasn't been disturbed. One woman at the preview conspiratorially shares her conviction that, dust or no dust, the "good stuff" most likely already has been rifled from the boxes.

"PBOs," or packed-by-owner boxes, also are considered more promising than boxes packed by the movers, says Beavers. Owners aren't as methodical as professional packers, and they might decide to wrap that leaded crystal heirloom vase from Granny in a blanket and label the whole box "bedroom."

A final theory popular with the box set: See if any moving or storage company employees are on site and note what draws their interest. They probably have insider knowledge of what boxes are worth having.

Clayton A. Martin's boxes look as though they could be worth having. Martin's name is on dozens of containers marked with everything from "stereo" to "kitchen" to "Xmas." Several old-fashioned trunks bearing his name are marked "clothing," and a broken hasp on one allows for a surreptitious inventory of some of its contents: leisure wear, all from a vanished lifestyle.

Clayton owned black watch plaid pants not often seen in recent decades and luxuriously soft tweed trousers, both lined. Must have been a man of means.

A half-dozen pairs of his cotton trousers in garish golfer colors are neatly packed atop a soft, creamy shirt bearing a label from a shop in Panama. But what size was Clayton?

Whoops, here comes the auction worker whose job is to police the preview and rebuke any sneak peekers. Still, enough was seen to evoke a vision of a Graham Greene character in tailored linen pants and soft Egyptian cotton shirt, sipping a cocktail on a veranda overlooking a tropical sea. Yes, indicators are that Clayton lived the good life -- at least until that fateful day 40 or 50 years ago when the movers lost his stuff.

Several footlockers marked "Katmandu" also are drawing tons of tilt tests. Heavy. An excellent sign. And promisingly dusty too -- tantalizingly grimy, even. Even more propitious, someone went to a whole lot of trouble to protect the footlockers with heavy wooden crating. Brown predicts heavy bidding action here.

Once the auction begins, Reger moves quickly, spending less than a minute on most items. When his voice starts to strain, Hopkins spells him. No dillydallying when the goal is to sell several hundred lots in about three hours.

The auctioneers and the crowd flow amoeba-like up and down the cavernous warehouse, past rows of desks (which went for $25 each), a soft-porn velvet painting ($5), a set of rattan chairs ($85) and, of course, lots of boxes. A policeman appears and casually strolls the aisles.

"Looking for stolen goods," whispers the same woman who believed all the good stuff had been pilfered long before the cop arrived.

Reger reaches the first Clayton boxes in about 30 minutes.

A pair of boxes marked "linens" go for $25, but a rule of storage auctions is that boxes cannot be opened on site. So whether the linens -- if linens they be -- came from Woolworth's or Harrods will remain a mystery.

The "Katmandu" crates come up about an hour into the auction.

Brown buys one of the smaller ones for $100.

Ted Hiller of Manassas, who came to the auction in search of furniture, plunks down $225 for another.

"It's like [going after] the prize in a Cracker Jack box," Hiller says, looking a little stunned by his unplanned purchase. He had intended to spend his money on a 19th-century washstand.

In a phone call the next day, Hiller pronounces himself "not totally disappointed" by his prize. His trunk contained 11 framed and signed pictures, including two charcoal rubbings, possibly from a Nepalese temple; a champagne bucket and a breakfast tray; and a toy bazooka. Definitely a PBO.

Brown says he often makes an event out of his box openings, setting up lawn chairs in the garage, opening bottles of wine and inviting the neighbors for a cross between a grand opening and a surprise party. But he can't wait to see the contents of the Katmandu crate and drags it into the alley off the premises where someone helps him break the lock with an ax.

A handful of onlookers crowd around to see what treasures might lie inside. They sigh:

A moldering game of Clue, a squashed summer hat that probably never was stylish, a Christmas tree skirt and some linens make up the top layer of the footlocker's contents.

Brown tries not to look too disappointed. He burrows deeper and comes up with a small cardboard box. Inside are filigree silver earrings and several watches. His face registers relief. Maybe he'll come out ahead after all.

Meanwhile, Brown has to hustle back inside. He has his eye on a promising-looking china barrel that the auction is fast approaching.

Clayton's trunks, though, won't come up for bid until almost the end of the auction, at least a 90-minute wait, and the warehouse chill is insinuating itself.

Does it make sense to wait around on a whim? I mean, who wears plaid pants these days -- even in the unlikely chance that they would fit the near and dear?

And if bidding goes crazy, to carry away Clayton almost certainly will mean having to get carried away yourself. Like you don't have better uses for 300 bucks.

Still, no harm in nipping out to the Saturn to eyeball the back seat just in case. After all, it's not like Clayton's trunk is the size of a roll-top desk ...

McAteer is the letters editor for The Washington Post and a freelance writer.