The prices at retailers like Wal-mart and Target have risen so fast that analysts say they can’t even begin to understand how they’re doing it.
The price war at retailers has been a boon for the big-box stores, which are among the largest purchasers of groceries.
And the companies have been particularly effective at capturing a share of the cost of groceries and other goods as consumers have shifted their shopping from stores like Target and Walmart to smaller chains.
But there are signs that prices are becoming more expensive at other retailers, too.
Target announced in December that it would start selling at its lowest price in nearly two years, and Costco will start selling its prices on Wednesday.
Costco has also started selling at a discount, with the average price dropping to about $9.95 per item.
That compares with a $19.95 average price for its lowest-priced goods.
Wal-Mart’s prices have been especially strong, analysts said, with its prices falling to $4.25 per pound from $8.95, and its average price down to $11.50 from $13.25.
Costco said it had no immediate comment.
Target and Costco both said they would not be commenting on the prices of their products.
Walmart said the price war “isn’t a good sign for our business,” and it said it was considering whether to increase prices.
WalMart said it would continue to increase the prices for all items in its stores, including food and beverage, which the retailer says is needed to help it compete with rivals.
But it also said it planned to offer more promotions that are targeted to shoppers who pay for them.
The companies are trying to get consumers to switch from shopping online to buying groceries and merchandise at stores.
Walmarts sales have fallen nearly 8% in the past year, partly due to falling gas prices.
In December, Walmart said it expected sales to fall 0.6% in 2018.
Costco is on a different trajectory, but its profit rose 1.7% in 2017 to $3.6 billion.
Costco’s profit rose 5.3% to $2.2 billion.
Costos prices are higher than some other retailers that also have lower prices, including Macy’s and Home Depot.
Walmart and Target both have lower average prices.
Target’s average price is about $11 per pound compared with $8 at Costco.
Costco sells food, beverages and electronics at a price range of $8 to $13 per pound, while Walmarts prices range from $15 to $20 per pound.