I took the same grocery list to Walmart, Kroger, and Amazon to compare prices. After filling my carts, I found a winner.

Walmart's press release specifically mentions a rollback on the 1-pound roll of 73% ground beef, so that's what I selected.

As promised, Walmart's beef, originally $6.94, came to $5.94 for a 1-pound roll. Kroger's was very close behind at $5.99.

I couldn't find any 1-pound packages of 73% lean ground beef on Amazon, only a bulky 3-pound roll. It worked out to $6.15 per pound.

Walmart's price was the lowest, but I wasn't particularly impressed by any of them.

Following publication, Amazon told Business Insider the 1-pound package of ground beef is largely out of stock. So, I decided to exclude this item from my basket total for all three retailers.

I can't comment on the actual sweetness in terms of taste, but Walmart's sweet corn was a bargain. It cost just $0.25 per ear, compared to $0.40 per ear at Kroger and a whopping $1.25 per ear on Amazon.

I added four ears to my cart at each retailer.

The Walmart press release specifically mentioned 2.2-pound bags of fresh red cherries would be reduced from $11.18 to $5.63, bringing the total cost-per-pound to $2.56. However, my local store only carried 1-pound bags, which came out to $2.50 per pound.

Kroger's 1-pound bags of red cherries were on sale, discounted from $4.49 to $2.99 per pound. Amazon's 1-pound bags tied with Kroger at $2.99 per pound.

It's worth noting that Kroger deals like these are only valid with a Kroger Plus Card — which I have, since it's a free loyalty card. Without it, they'd have cost me the full $4.49.

I was also surprised to find such a great sale in the store since I hadn't seen it mentioned in Kroger's weekly flyer. I wondered if it may have been a more last-minute discount to compete with Walmart after the Monday announcement. Kroger did not respond to Business Insider's request for comment.

Walmart highlighted 48-ounce tubs of its store-brand Great Value ice cream being reduced from $2.97 to $2.50. That's exactly what I found in the store.

Amazon had the same-sized tubs of Amazon Grocery ice cream available for $2.97, the price Walmart's was before the cut.

Kroger had the cheapest 48-ounce tubs on sale for $1.99 — marked down from $2.99. With prices this good, I would have happily bought ice cream from all three retailers.

An 8-ounce bag of Lay's classic potato chips cost $2.50 at Walmart, marked down from $2.97. The same bag of chips was also $2.50 on Amazon.

At Kroger, these chips had several prices in front of it. The 8-ounce bag was originally priced at $3.99, listed at $3.29 with card, and then labeled $1.99 with card and a clipped digital coupon as part of a weekly deal.

Kroger's price was the best, but I only just caught this deal, which expired July 7. (Kroger's digital deals refresh every Wednesday, and I visited Kroger on a Tuesday.)

At the time of writing, the deal is already gone.

Walmart reduced the price of the Frito-Lay Family Fun 18-bag variety pack including a mix of Cheetos, Fritos, Funyuns, Lay's, and Ruffles from $9.97 to $8.97.

Kroger originally listed the variety packs at $10.99, but price-drop stickers now had them marked $9.99.

On Amazon, this pack was available for $9.99 through Amazon Fresh, which I didn't use because I'm already a Prime member and wasn't ordering enough to hit the minimum spend and avoid a delivery fee.

My other option was to order this pack through a low-rated third-party seller for a whopping $21.

Because this item wasn't readily available to me on Amazon, I decided to exclude it from my total basket price for all three retailers.

Walmart's release highlighted a 200-pack of Great Value disposable plates being marked down from $9.97 to $8.97, or $0.04 per plate.

On Amazon, the same quantity of Amazon Basics plates was $10.60, or $0.05 per plate.

My local Kroger didn't have any 200-packs, and the closest I found was 150 plates for $9.99. They worked out to $0.07 per plate.

If I ever need such a large quantity of disposable plates, I'm totally turning to Walmart or Amazon.

However, because this wasn't a true like-for-like comparison, I excluded this item from my total for all three retailers.

Walmart marked down select 24-packs of sodas, including Coca-Cola and Diet Pepsi. With the rollback prices, they worked out to $0.42 per can.

My local Kroger didn't have any 24-packs of these drinks, so 12-packs were the next best option.

Kroger's a 12-pack of Coca-Cola or Pepsi cans typically costs $11.99, or $1 per can. However, when I visited, the store was running a "buy two, get three free" deal, which meant I could get 60 cans for the price of 24. It brought the price per can down to $0.40.

Although Amazon offers 24-packs of soda, I didn't see any available in my area that day. However, I could buy 12-packs, so I grabbed two of each. On Amazon, my Coca-Cola came to $0.70 per can, whereas Diet Pepsi was $0.66 per can.

Because the soda-pack sizes varied, I excluded this item from my basket totals to ensure a fair comparison.

Unlike Walmart, where rollbacks tend to last several weeks and are available to any shopper, many of Kroger's sale prices only last for seven days and require a (free) rewards membership to claim them.

If I hadn't gotten lucky with the deals running that week, or if I didn't have a Kroger card, I could have easily shelled out about $30 or more for the same cart.

Like Kroger, Amazon's prices change often, for better or for worse. I could see exactly how much by using the "price history" feature. For example, the 12-pack of Coca-Cola alone ranged in price from $6.29 to $8.89 over the past 30 days.

On the bright side, Amazon's prices came with the most convenience: I wouldn't have to drive anywhere or pay for delivery, given that I'm already a Prime member. (The membership costs about $139 a year and comes with other perks.)

My Walmart cart, complete with four of the nine categories of items, including the corn, cherries, ice cream, and potato chips, came to $8.50.

My Kroger cart — using my card and the deals available at the time —came to $8.57.

In my opinion, the closeness of the totals made Walmart's price reductions feel a little less impressive — especially since Walmart had a slight advantage in dictating which items I compared.

My cart of four Amazon items came out to be the most expensive at $13.46.

None of the retailers had the cheapest item in every category, but if it weren't for my seemingly lucky week and Kroger card, Walmart would have.

Walmart got me the lowest-priced basket this time — though the savings weren't as big as I'd expected, given that I specifically shopped the chain's price-dropped items. Kroger really held its own in this battle.

Even so, I'd definitely keep an eye out for Walmart's future rollbacks and Kroger's weekly coupons and deals. I also plan to keep my perk-filled Amazon Prime membership.

This particular price drop aside, I've often found competitive grocery prices at Walmart, and I appreciate how the chain's rollbacks typically last at least a few weeks.

Since most of Kroger's deals change weekly, I sometimes miss discounted prices before I even realize they're available. Amazon's prices seem to fluctuate fairly often.

In the end, the best value comes down to what groceries you need and the current deals available at each place when you buy them.

And, hey, I certainly wouldn't complain if other retailers want to follow Walmart's lead and drop more prices this summer.

Correction: Following publication, Business Insider reviewed the product comparisons and updated several items to ensure they were like-for-like in package size and product type. If items found in stores, were not like-for-like, they were excluded from the basket totals. Basket totals have been recalculated accordingly.