Even with the discounts offered to Amazon.com Inc.’s Prime members, the cost of a $400-plus broad basket of items purchased at Amazon-owned Whole Foods Market only yields $1.50 in savings over prices one year ago, Gordon Haskett Research Advisors found.

Since buying Whole Foods Market in 2017, Amazon AMZN, +0.86% has announced a number of new perks and promotions, particularly for Amazon Prime members, including an additional 10% off Whole Foods sale items and Prime Now delivery in as little as an hour in dozens of cities for Whole Foods grocery purchases.

The Amazon Prime Rewards Visa V, -0.28% card, introduced in February, also offers 5% back on Whole Foods purchases.

But one expected perk — a notable decrease in prices considering Amazon’s vast network — has not come to pass, according to analysts led by Chuck Grom.

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“While deeper promotional pricing on key items, incremental savings… and increased convenience for Prime Members in the first year under Amazon ownership have caught our eye as consumers, the reality is that Whole Foods pricing on a broad basket has remained largely unchanged,” the Gordon Haskett note said.

Analysts priced a basket of 108 items at the end of August 2018, the last time they conducted the price test since they began the analysis in August 2017. A week after the first trial, when the acquisition closed, they visited the Princeton, N.J., location to conduct the second test. The other price tests were in late September 2017, November 2017 and March 2018. Pricing remained largely consistent, analysts said.

Among the items in the basket were Whole Foods’ 365 brand creamy peanut butter, light balsamic vinaigrette and coffee ice cream. Cheerios, Nature’s Path buckwheat and wild berry waffles and Amy’s Breakfast Tofu Wrap were in there, too.

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“The current basket is priced below our pre-merger pricing (-80 basis points versus 8/21/17), but 130 basis points above levels from a year ago when the deal closed and the company completed its first round of price investments,” the report said.

Compared with late March, the analysts found higher prices on 19 items in the basket, while 11 items had lower prices and 78 items were priced the same. There were also fewer sale items included in their basket.

Analysts said factors like “modest inflation” and increased fuel costs have also driven up prices.

Since acquiring Whole Foods, Amazon has offered discounts on holiday-specific items like antibiotic-free turkey around Thanksgiving, and lowered prices on avocados and kale.

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Before the acquisition, Whole Foods grappled with the persistent “Whole Paycheck” reputation that made Whole Foods synonymous with high-priced groceries that often featured specialty items and locally produced offerings.

Nevertheless, the Amazon/Whole Foods combination is forecast to transform the grocery business, with online grocery sales climbing and competition with major grocers like Walmart Inc. WMT, -0.02% and Kroger Co. KR, -0.21% heating up. Use of grocery apps has increased by nearly 50% according to eMarketer data.