Dive Brief:

Amazon's prices on Black Friday and Cyber Monday were 11% higher on average compared to other retailers, according to a holiday price index of 59 top holiday gifts from price tracking and comparison tool Wikibuy, which compares "all-in prices," which include shipping and tax to give a better idea of what consumers actually pay, a Wikibuy spokesperson told Retail Dive.

Amazon believes the findings are inaccurate. “We think the Wikibuy research is deeply flawed and misleading," an Amazon spokesperson told Retail Dive in an email. "Customers come to Amazon to find low prices and great deals throughout the holiday season, and we continue to offer customers thousands of incredible deals on top products for their holiday shopping needs. Amazon prices are as low or lower than any other retailer, and we work hard for customers to ensure that’s true during the holiday season, and all year long. In addition to low prices, we offer customers a vast selection, and more than 100 million items that are eligible for free shipping to all customers, every day.”

Amazon did beat Walmart, Target and other retailers for some of the most in-demand items, according to another report from Boomerang Commerce emailed to Retail Dive. Still, deals around Black Friday weren't necessarily all they were cracked up to be on a lot of sites, according to Boomerang Commerce. Retailers including Amazon, Walmart, Target and Toys R Us were offering deals on top items, but pricing really hadn't changed much from even up to a month earlier, even though they were being marketed as a Black Friday deal, Boomerang said.

Dive Insight:

After simply looking aghast at the margin-killing numbers offered by Amazon, retailers have begun to fight back with price-matching, price-slashing and even attractive delivery rates on online orders. Now with a formidable and loyal customer base in its potentially 90 million U.S. Prime members and with the help of dynamic pricing, Amazon may be shifting to a convenience and content proposition, as opposed to a best-price proposition. Prime members enjoy free two-day shipping on most items and have access to a streaming entertainment service, plus smaller perks like photo storage and music streaming, among others. (The actual size of Prime membership, which Amazon does not disclose, is up for debate).

Amazon's price scraping and dynamic pricing algorithms helped it grab a price advantage in some cases, Boomerang contends, citing prices like that for Beats Solo3 Wireless Headphones (Target’s Black Friday deal was $239.99, while Amazon's in-cart price was $198.99). But specialty retailers fared worse. Out of 18 items shipped and sold by Amazon that also appear on Sur La Table’s first page of Black Friday deals, 10 were cheaper on Amazon.

Best Buy in particular is playing offense, according to Boomerang. With indications last year that Amazon was attuned to Best Buy's pricing, Best Buy's ability this year to beat Amazon on price for top items like the Sony 60-inch LED Smart 4K Ultra HD TV ($599.99 at Best Buy, $648 at Amazon), suggests that Best Buy has been able to negotiate exclusive offers, according to Boomerang's report.

But shopping exclusively on Amazon meant losing out on lower prices in every category studied by Wikibuy, which from April 24 to Dec. 3 tracked prices at Amazon and at Wikibuy’s list of "thousands of e-commerce sellers, including major retailers, brands and other small retailers." The larger retailers in Wikibuy's research include, along with Amazon, Kohl’s, Target, eBay, Walmart and Jet.

Some of the biggest savings were on electronics, like the Samsung 60-Inch 1080p Smart LED TV ($448.52 average savings), according to Wikibuy. Shoppers using the Wikibuy app saved an average of $108 on TVs and $20 on electronics. Even Amazon’s own products could be found on other retailers' sites for less: The average Black Friday week price for the Echo Dot (2nd Generation) was $38.52 on Amazon, but $33.08 via Wikibuy — a 16% savings. That Echo Dot has been on sale for $29.99 (it’s lowest price ever) since the week of Black Friday, through to today, however, according to Amazon.

Wikibuy found that prices on items steadily decline starting in late summer, with the most drastic drop, unsurprisingly, during Black Friday week. Days beyond Black Friday, many products remain priced lower than they are during the rest of the year, according to Wikibuy and holiday deals site BestBlackFriday.

But Prime members turning to Amazon without shopping around may be the ones over-paying. Costco, for example, consistently beat Amazon on price, sometimes by huge margins, according to research from online student loan refinancing marketplace LendEDU. Items on Amazon on average are 56.48% more expensive than the same products found at a Costco store shopped by LendEDU researchers. Walmart is also closing the pricing gap with Amazon, according to research by retail data analytics firm Market Track.

Holiday Price Index Wikibuy

That matches up with similar research from e-commerce analytics firm Profitero last month, which found that, on average, Walmart's prices were just 3% higher than Amazon's across 13 categories. Walmart was priced lower than Amazon in beauty (the only category where it actually beat Amazon) and came close in sports and outdoors, and baby products, Profitero found.

Wikibuy's holiday study comes a few months after its similar analysis of back-to-school prices, which found that Amazon shoppers overpaid by 15% on average for school supplies. Amazon’s prices changed hour-by-hour, state-by-state and shopper-by-shopper, according to Wikibuy's May study. The extension searches other sites, including Walmart, Jet and eBay, and its price comparison tool shows potentially cheaper options, including tax, shipping and any coupons that apply for Chrome browser users.

This story is part of our ongoing coverage of the 2017 holiday shopping season. You can browse our holiday page and sign up for our holiday newsletter for more stories.