Just two months ago, Amazon announced it would purchase Whole Foods Market. The $13.7 billion deal was finalized on Aug. 28, when Whole Foods shoppers saw prices drop immediately — as much as 43 percent on some staples, according to Bloomberg.

Jeff Wilke, CEO of Worldwide Consumer at Amazon, said in a statement the company would "lower prices without compromising Whole Foods Market's long-held commitment to the highest standards." And on the first day of ownership, the company held true to its promise. Staples like organic avocados told the story, dropping in price from $2.79 on Aug. 24 to $1.99 on Monday. You may be able find a better price at another store — the average price for an organic Hass avocado is roughly $1.71, according to this chart — but a drop of 29 percent is notable.

Shoppers can expect to see savings on some of Whole Foods' most popular items like salmon, baby kale, almond butter, bananas, eggs, ground beef, rotisserie chicken, butter and apples.

The Amazon Prime connection

In addition to cutting prices for all shoppers, Amazon Prime members will eventually get special discounts and in-store benefits. It's estimated that 70 percent of Whole Foods shoppers are already Prime members.

Although Whole Foods will be keeping its name, there will be some crossover between Amazon and Whole Foods. After the sale goes through, Amazon customers can expect to start seeing some items from the Whole Foods private labels (365 Everyday Value, Whole Paws and Whole Catch) on Amazon.com. Some Whole Food stores will add Amazon Lockers, self-service delivery locations where customers can pick up and return Amazon.com packages.

On the first day of Amazon ownership, the Amazon Echo was on sale at some stores for $99.

Back in June when the impending sale was announced, stocks of some competing grocery chains fell immediately and that played out on Monday as well. Critics have warned that the marrying of the two companies eventually would lead to higher grocery prices and fewer consumer choices as Amazon squeezes out other grocery chains. There's also a concern that suppliers who don't have scale — a large enough quantity of whatever they supply to satisfy the Amazon way of doing things — will also be affected.

The green light for the sale to go through from both the Federal Trade Commission and Whole Foods shareholders did nothing to alleviate those concerns. Business Insider reports that Target's stock lost 4.2 percent. Walmart, the largest grocery seller in the country, saw a 2 percent drop. Kroger's stock was down 8.3 percent and Sprouts Farmers Market went down 6.6 percent.

This story was originally written in early August and has been updated with more recent information.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.