So you think you're a wise consumer? You check the newspaper for the supermarket specials and clip the coupons for the cents-off sales. You ''comparison shop'' when it's time to replace the family transportation. You wait for the white sales to pick up sheets, pillowcases, and towels. What else can you do?
If you're like millions of other Americans this year, you might be contemplating disposing of the surplus household goods and dusty bric-a-brac filling the back of the closet by holding a yard sale. That would be a smart idea, and could supplement the household revenue, right?
Not necessarily. Like so many ideas that sound great originally and later turn to disaster, holding a yard sale, depending on what you have for sale, could be a big financial mistake.
Consider the case of the Long Island family who decided in the summer of 1981 to clean out their surplus via a yard sale. Among the offerings displayed on a card table was a small porcelain sweetmeat dish. One of the browsers picked it up, looked at the $2 price tag, and promptly bought it.
Last Jan. 28, the dish, only a little over five inches tall and consisting of a tiny bowl atop three shell-like forms, went across the auction block at Sotheby's York Avenue Gallery in New York City. A New York dealer, a specialist in American ceramics, emerged the new owner after spirited bidding against the Philadelphia Museum of Art and a private underbidder. The price: $66,000 (including 10 percent buyer's commission)!
What changed a $2 dish into a $66,000 antique? Nothing but the knowledge of the yard-sale buyer, who spotted the underglaze blue painted letter ''P'' on the bottom of the dish. He recognized it as the mark of the first porcelain factory in America, Bonin & Morris of Philadelphia. Since at the time there existed only 14 pieces from this 18th-century factory (and most of those only fragments), this sweetmeat dish was a rarity.
What are the chances of your owning a piece like that? Frankly, minuscule, but you may own a piece worth many times what you would mark it at a yard sale. Each year thousands of antiques make their way from yard sale to picker to dealer to auction to collector, all with corresponding price increases along the route.
Almost every dealer has a similar story to tell. ''My picker brought me this butter mold. He bought it for $6 at a yard sale. I paid him $35 for it and priced it fairly at $65. Of course, I'll have to wait awhile to get it, but it'll eventually sell for that. Sure wish I could have bought it for $6, though!'' Silver, glass, paper, fabrics, copper and brass, furniture - similar histories can be found in each category.
What can the average person do when it appears that among the bric-a-brac being gathered up for the yard sale there is one piece that might have antique value? The first step involves discovering just what it is you own. Visit your local library and read through books on antiques. Match up your piece with similar examples. Check out the antique price guides. If you have a friend who collects or knows antiques, seek his or her opinion. Be aware of family tradition. If your grandmother always insisted that the old green decanter was blown at the local, long-defunct glassworks, check it out.
The larger auction houses will have appraisal departments. Some feature walk-in service. Take your antique, or several good photos of it, to them. It will cost you a small fee for that service, but it could be one of the better investments you'll ever make. If the piece is good, they may want to auction it for you. Sometimes they will lower, or even negate, the appraisal price if that happens.
Finally, you could call in an independent appraiser. For either a fixed fee or an hourly rate, the appraiser can determine the value of those objects you are in doubt about. This approach would be most feasible if you had several pieces. Whatever method you choose, find the true value of your antiques. The choice to sell or to keep is now up to you. If one of your belongings does have antique value, the yard sale route is no way to sell it. Take it to a dealer or consign it to an auction.
Let's face it, the chances of your finding a $60,000 piece among your chipped plates and faded 1920s prints are, to be gracious about it, extremely slight. But every now and then it does happen. There among the flotsam and jetsam of some yard sales sits a piece worth its weight in gold.
Don't make the mistake rumored to have been made by a Massachusetts family who sold an oil on canvas last year for $20 at a yard sale. That painting, a folk art piece of great desirability and Ohio origin, was sold at auction later in the year for $33,000. That kind of money will buy a lot of groceries for a coupon-clipping family.