Finding the lowest price online isn't always easy

King of the pricing jungle? Amazon
King of the pricing jungle? Amazon   

"Where can I get the lowest price?" should be an easy question to answer. But it's not always so simple.

Thanks to a slew of factors ranging from shipping fees, special offers linked to credit cards and price-matching guarantees, it can be difficult for shoppers to find the best possible price on an item. Making things even more complicated are retailers' sophisticated algorithms, which respond to changes in the marketplace and sometimes adjust prices more than once a day.

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Excluding these complexities, CNBC teamed up with personal finance website NerdWallet to track base prices on 11 consumer electronics products over 12 consecutive weeks at Target.com, BestBuy.com, Amazon.com and Walmart.com.

For the purposes of the study, which was conducted using NerdWallet's DealFinder tool, the base price was only adjusted when the retailer offered a gift card with the purchase. Products examined included a Fitbit Flex, Sony PlayStation 4 and a 16-gigabyte Apple iPad Air.

According to the findings, Amazon ruled the pricing jungle, with Wal-Mart coming in a close second. In some cases, Amazon noted that its price advantage came from its third-party seller marketplace, where it does not influence pricing. Target and Best Buy most often tied for the highest online prices.

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NerdWallet senior retail analyst Matt Ong said that Amazon and Wal-Mart have the most advanced pricing software algorithms and that "It looks as if Target is either choosing not to play the [pricing] game, or is just not as advanced in its [pricing] technology."

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In response to the study's findings, spokespersons for Target, Best Buy and Wal-Mart all pointed to their price-match guarantees. Rafi Mohammed, founder of pricing strategy consulting firm Culture of Profit, said price-sensitive consumers can almost always get the best price at any retailer by taking advantage of price-match policies available—so long as they're willing to invest the time.

A separate finding from the CNBC/NerdWallet study found Best Buy had the top track record for being in stock. Only one of the items included in the study was out of stock one time during the 12-week tracking period.