Why to shop where

The prices are good. (That doesn't mean cheap. Recently a Costco store in Orange County advertised a 3.12-carat diamond for $73,199.99. Who knows what it would have cost at Cartier?) It's all about volume, whether you're interested in tires or silver bangles. "Wal-Mart, as we all know, drives incredible bargains through their vendor base," says Debra Stevenson, president of Skyline Studios, an L.A. consulting firm, and so do its rivals. Some consumers swear by them. "Costco and Sam's [Club] have the best jewelry prices," says Rita Bailey, a teacher from Huntington Beach. Mary Ann Beyer, a retired emergency room nurse from the same city, likes Costco because she can "shop freely" without being pestered. And "at Tiffany or Cartier," she says, "you're just paying for their name."

Two words: the box. At Tiffany's, it's robin's egg blue, at Cartier's, red. The posh places deliver their gems in iconic boxes, and it's impossible to appraise their value. Rachel Parker, an 18-year-old who lives in Corona del Mar, opened her first from Tiffany's when she was in the eighth grade (inside: a heart dangling from a sterling silver chain). "As soon as I see the blue box, I know I can count on liking it," she says. The conventional consumer wisdom is that you pay quite a sizable premium. There's no question in some minds that whatever it is, it's worth it. Tiffany's chief gemologist, Peter Schnerla, says a purchase comes with a guarantee. "If the customer is unhappy, for whatever reason, we will make them happy."

There are miles of sapphires, gold, diamonds, beads, turquoise, rubies, silver, both real gems and paste -- and you can haggle with the merchants. "They expect it," says Cosmo Altobelli, owner of Altobelli Jewelers in North Hollywood and an appraiser with nearly 60 years of experience. "If you don't, they'll probably think you're sick." For some, the thought of thousands of vendors can be overwhelming. Not for Eddie Reay, a 29-year-old from Woodland Hills who found an engagement ring there -- and a rush. "I just ran from store to store," he says. The trick is to get "a feel" for the district by visiting often and developing relationships, says Carol Wade, a Buena Park resident. "It's a lot of trial and error."

You don't have to get out of your chair to shop the endless Internet terrain of jewelry sellers. If you trust online merchants for your most pricey purchases, you could save a chunk of change because online-only stores have less overhead than bricks-and-mortar places. A 1-carat round brilliant cut diamond, VS-2 clarity and G color (one of the most popular on the Web) would cost about $6,000 online and about $8,000 at a typical retail store, says Michael McGivern, a co-owner of McGivern Diamonds, which operates Overnightdiamonds.com. Be sure to do business only with an outfit with a solid return policy, pay by credit card (so you can dispute a buy) and purchase gems certified by the GIA or AGS.

Moderate prices, frequent sales and convenience -- what else do you want? At the mall (or at jewelers like Zales, which are not always located in a shopping center) you'll no doubt find better payment options and more reliable return policies than in, say, a jewelry district. "The question is, what are you trying to accomplish?" says Marshal Cohen, chief industry analyst for NPD Group. "If you're looking for low prices, good enough quality -- not heirloom jewelry -- then mall-based retailers are the perfect places." Fix your priorities, do the math, then make your decision. "It comes down to a simple equation," Cohen says. "You pay more and you're going to get more service.