Consumer Reports found savings of 15% to 61% on an assortment of goods, while Cheapism's comparison-shopping trips yielded saving of 30% on average, Levitte said. Value Retail News, a trade magazine, reports that the average savings at outlets are about 38%.

Moreover, the discounts are based on the manufacturer's suggested retail price, which is rarely what people pay. And though Banana Republic's suggested price for a T-shirt will be the same for outlets and regular retail stores, it's not an apples-to-apples comparison, Levitte said.

"That retail price is irrelevant in many cases, because those items were not available at retail and were always meant for outlet stores," he said.

"Sometimes products are the exact same price and the exact same product in both mall and outlet stores," Cheapism's Levitte found. His best example: a Kate Spade iPhone case.

"One of the brands told us that they see outlets as just another place to display their merchandise," Levitte said. "They don't think of it as a cheaper place but as another venue."

Given that, he encourages consumers to shop department store sales and coupons before heading to an outlet mall for things like jeans, shoes and leather goods. Do twice-yearly outlet shopping for socks, underwear, T-shirts and other clothing necessities.

"The selection is much bigger at retailer malls, and many retail stores will give you a better value" when sales and discounts are factored in, Levitte said.

He points to Samsonite suitcases, which are often better quality at Macy's retail stores than at outlet malls, making them a better value at Macy's if they're on sale.

Still, there are tricks to making your outlet shopping a positive, money-saving experience, according to Consumer Reports:

  • Be strategic about your shopping. Go to the outlet's website to map store locations so you can park and shop without walking for miles.
  • Contact the mall's management office and ask about any sales beyond the ones found online or in circulars. Some malls also offer deals for seniors and members of the military.
  • Get price breaks through exclusive promotions and rewards programs. Premium Outlets offers a free VIP Shopper Club registration and the Tanger Outlets Club has one for $10. You can also sign up for email alerts and become a fan on Facebook for bigger savings.
  • The early bird gets the best deals. By shopping early in the day, you avoid the crowds, and the merchandise is at its freshest for the day. Avoid noon to 3 p.m., when crowds are at their peak.
  • Shop on Tuesdays, Wednesdays or Thursdays, and stay away during the holidays.
  • Shop for summer things in the winter and winter things in the summer. Off-season goods typically come at bargain-basement prices.
  • Remember that what you buy may not be returnable. Many regular retailers won't take returns from outlets.
  • If you're unsure about the mix of products at your favorite outlet mall, just ask. The clerks who spoke to both Consumer Reports and Cheapism were very candid, the two said.

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