With the proliferation of price-comparison apps that give mobile device users a competitive edge, there's no excuse these days for getting had online or in the store.
Many enable bar-code scanning to compare the best deals, plus price-drop alerts on everything from technology and travel to groceries and gasoline.
As mobile app technology evolves, others are rolling out price predictions based on retail trends, offering gift-giving insight and delivering a definitive answer for which store offers the better bargain after rebates and coupons are factored in.
With all that data on demand, consumers this holiday season could save big, said Mark Spoonauer, editor-in-chief of "Tom's Guide," which publishes product reviews and buyers' guides.
"Competition for the lowest prices is really heating up," he said. "I think a lot of retailers have woken up to the fact that consumers are showrooming (or browsing products in the store that they plan to purchase online for less), so stores like Wal-Mart and Best Buy are telling customers this holiday that they will match the prices they find on Amazon.com and other online retailers."
Not all price-comparison apps, however, are created equal. "At first glance, many of these apps look the same, but there are some pretty significant differences between them," Spoonauer said.
Among the standout apps that offer bar-code scanning, for example, is Red Laser, according to "Tom's Guide."
The app incorporates price-comparison features to pinpoint the lowest prices available on scanned items in both online and brick-and-mortar retailers. It also highlights product reviews and allows users to store their loyalty card information directly on the app for greater convenience.
Similarly, PriceJump lets shoppers scan bar codes and compare prices from stores near them and at more than 5,000 online vendors, including Amazon.com. The Amazon app allows users to compare online prices, read customer reviews and place orders from their phone.
In addition to price comparisons, ShopSavvy also offers price alerts. Consumers can tag the items they want to track and receive notices the minute they go on sale.
Another app, ShopAdvisor, offers a personal shopping concierge, distributing inside knowledge on when, where and what to buy, based on the items users select. The app partners with industry-leading magazines to deliver personalized recommendations on fashion items, home goods and editors' picks.
For its part, RetailMeNot takes price alerts one step further, using location technology to notify users of deals from stores they select. "When you walk into a mall, we immediately alert you to what deals are available at your favorite stores," said RetailMeNot spokesman Brian Hoyt. "We're a pioneer in location-aware technology, which gives our users more of an informational experience."
Spoonauer cautions, however, that shoppers should limit the number of price-alert apps they download.
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"I love price-drop alerts, but just make sure you stick with one shopping app that uses your location, because even when it's not open, it can really impact your battery life," he said. "Make sure in your settings that you're being judicious about which apps can use your location at any one time."
It's tough to keep track of the endless parade of coupons, rebates and rewards promotions advertised daily. Thanks to deal aggregator apps, however, you no longer have to.
8coupons, Yipit, OpenSky and others of their ilk cull together the best prices and offers from online and local retailers, helping shoppers quickly ferret out the deepest discounts on products they prefer.
RetailMeNot, named one of the seven best shopping apps of 2015 by Consumer Reports, also allows users to scan deals from their favorite stores, compare prices after promotions and present coupon codes to the cashier directly from their smartphones.
"You might find that what looked like the second or third best price from a specific retailer is actually the best deal overall when you use a coupon or rebate," said Hoyt.
BuyVia does it all, too, offering price comparisons, mobile couponing, price alerts and product reviews — along with secure online shopping.
Mobile shopping apps aren't just limited to items at the mall, however. They exist for nearly every segment of the market.
Consumers who wish to find the lowest price at the pump, for example, can download Gas Buddy, Gas Guru or Waze, while those who seek to save on the soaring cost of medication can turn to tech as well.
The LowestMed app, for example, compares prices for brand name and generic prescription drugs at supermarkets and pharmacy chains close to home. GoodRx does the same, noting the coupons and savings tips it provides can save its users 50 percent or more on prescription costs.
Lastly, travelers can lighten their load by using airfare alerts, consumer ratings and price-comparison apps that cater to their needs.
Kayak, Airfarewatchdog, Orbitz and Hipmunk all offer fare alerts to destinations on your wish list. Hotwire tracks hotel- and car-rental deals, and TripAdvisor includes restaurants, flights and rental cars.
Armed with mobile apps, consumers today are better equipped to make smart buying decisions.
But price-comparison tools and coupon aggregators deliver another important benefit as well — keeping retailers on their toes.
"Even Amazon's own app has a bar-code scanner built in, which should probably send shivers down the spine of retailers everywhere," said Spoonauer.
— By Shelly Schwartz, special to CNBC.com