Bargain basements giving way to boutiques

Bargain basements for prestige department stores - and for other merchandisers, too - are out. At least that's the way selling space is shaping up in many parts of the country for store-distressed goods. One reason, according to marketing analysts, is that customers nowadays are accustomed to looking for marked-down bargains in regular store departments - not in separate downstairs locations.

More important, though, is that selling space in what used to be bargain basements has become valuable, profitwise, for stocking high-margin items like candy shops; one-item, high-style boutiques; gourmet cookery; French-style hot-bread bakeries; and even intimate in-store restaurants.

But all stores need clearance selling space. And to get it, some are going ''clear across town'' to locate in garment-center-type locations. These premises are usually converted malls or warehouses now catering to off-price, discount, and clearance-good entrepreneurs. Major department stores now are even lending their own prestigious real names (So-and-so's Home Clearance Center) to the operations in which they are pushing the bargain-price aspects of the stocks to garment-center weekend customer traffic.