Recently, I asked our readers to fill out a survey about grocery shopping habits, including where you shopped and what was on your most recent receipt. Thank you to the 53 readers who shared their data! I have been volunteering hard over the last half-month to bring you the most representative grocery index I could, and I think the results will be helpful no matter how you shop.
Last year in April, we published data with an index, but that was not representative of a reader survey.
The bread and frozen foods department of the Cub Foods in The Quarry. Photo: AuthorFirst, some takeaways from the reader survey.
The first question I asked was which local grocery option our readers shop at. Readers could select as many options as they wanted. The top choices were Cub Foods and Local Co-Op both with 52.8%, Lunds & Byerlys with 43.4%, and Target with 41.5%.
For Local Co-ops, I asked where people shop. The top answers in order of popularity were Seward, Wedge, and a tie between the Mississippi Market and Seward Friendship Store.

The top choices were Cub Foods and Local Co-Op, both with 52.8%.
To create a representative index of grocery buying for our readers, I asked what was on your most recent receipt or what you could recall from memory. The top items included were milk, eggs, mozzarella cheese, and chicken, which I standardized as fresh chicken breast and frozen chicken breast. You can check out the full list of items and weights on the Google Sheets spreadsheet that shows all the math behind this index.

The produce department at the Cub Foods in The Quarry. Photo: Author
Finally, with the knowledge that organic prices are usually different than conventional prices, I asked on a sliding scale from 0 to 10 what proportion of readers’ groceries were organic. The responses had a very flat distribution, and the average response was 4.5, or 45 percent organic.

The average was 45 percent of grocery shopping for our readers is organic.
Next the prices.
You can check out the full list of weights, items, and prices on the Google Sheets spreadsheet that shows all the math behind this index.
I compared prices at eight stores from February 5 – 16. The stores were: Aldi, Costco, Cub Foods, Kowalski’s, Lunds & Byerlys, Seward Co-op, Target, and Whole Foods. If an item wasn’t currently in stock, I recorded the price of the best option in that item class. For instance, in “milk”, skim was not always available, so I have some prices for one or two percent milkfat. I did not do this for conventional versus organic items. They are priced separately.
For the top five-weighted items — milk, eggs, mozzarella cheese, fresh chicken breast, and bananas — I found that there was no single best store for all these conventional (not organic) staples.
Store | Milk Price (gallon) | Eggs (egg) | Mozzarella Cheese (ounce) | Fresh Chicken Breast (pound) | Bananas (pound) |
Aldi | $2.66 | $0.11 | $0.22 | $1.89 | $0.65 |
Costco | $2.45 | $0.14 | $0.16 | $2.99 | $0.46 |
Cub Foods | $2.99 | $0.09 | $0.29 | $3.99 | $0.59 |
Kowalski’s | $3.19 | $0.14 | $0.40 | $7.99 | $0.73 |
Lunds & Byerlys | $2.99 | $0.14 | $0.31 | $7.99 | $0.63 |
Seward Co-op | $3.79 | $0.29 | $0.41 | $6.99 | $1.29 |
Target | $2.29 | $0.21 | $0.25 | $1.99 | $1.16 |
Whole Foods | $4.19 | $0.22 | $0.37 | $5.49 | $0.49 |
Costco had the best price on two of the top-weighted staples – mozzarella cheese and bananas – while ALDI, Cub Foods, and Target had the best prices on one of the top five.
After gathering price data for all the conventional (not organic) grocery items, I crunched the numbers using the weighting based on the survey. For a hypothetical grocery run for conventional items, Costco came in cheapest at $100.00, while ALDI came in at $103.08, and Target at $119.70.

Costco has the lowest prices on conventional groceries for a hypothetical grocery run using our weighted index based on the 2020 survey.
The median American household spends about $7,000 on food per year, according to 2018 data from the USDA. For the $60 membership to Costco to break even versus spending at ALDI, a household would have to spend at least $1,948 at Costco – significantly less than median household spending.

As their incomes rise, households spend more money on food, but it represents a smaller overall budget share. In 2018, households in the lowest income quintile spent an average of $4,109 on food, representing 35.1 percent of income, while households in the highest income quintile spent an average of $13,348 on food, representing 8.2 percent of income. Source: USDA
For organic groceries, Costco was also the highest value store. For a hypothetical grocery run for organic items, at Costco it would cost $100.00, at ALDI $101.26, and at Target $132.21.

Costco has the lowest prices on organic groceries for a hypothetical grocery run using our weighted index based on the 2020 survey.

It’s very hard to beat the Costco price. Photo: Author
Some thoughts from my experiences being a secret shopper for our readers:
Generally, the stores that advertised their prices more prominently, as with the above large-print sign at Costco with price per pound, were lower priced. ALDI and Costco were good about making the price clear. Kowalski’s and Seward had missing or fallen price tags, I found, and the price per ounce or other metric was nearly impossible to read.

Ultra. Ultra. Ultra! Photo: Author
There is also a compromise between choice and price. Kowalski’s was a great grocery experience with a delicious and well-priced hot bar and wide selection of deli and sushi. But having all that selection creates high overhead costs, and Kowalski’s turned out to be one of the most expensive grocery stores in this month’s survey.
Before you ask again, here were the dates and addresses of the different grocery stores where I went as a secret shopper. I did buy at all the stores, as a thank you for their hospitality. All prices reflect sales at the date of secret shopping.
Store | Location | Date |
ALDI | 1311 E Franklin Ave, Minneapolis, MN 55404 | February 7, 2020 |
Costco | 5801 W 16th St, St Louis Park, MN 55416 | February 16, 2020 |
Cub Foods | 1540 New Brighton Blvd, Minneapolis, MN 55413 | February 5, 2020 |
Kowalski’s | 2440 Hennepin Ave, Minneapolis, MN 55405 | February 16, 2020 |
Lunds & Byerlys | 25 University Ave SE, Minneapolis, MN 55414 | February 7, 2020 |
Seward | 2823 E Franklin Ave, Minneapolis, MN 55406 | February 16, 2020 |
Target | 1650 New Brighton Blvd, Minneapolis, MN 55413 | February 5, 2020 |
Whole Foods | 222 Hennepin Ave, Minneapolis, MN 55401 | February 8, 2020 |
I hope this helps you in your search for the best deal and best value for you and your household.
Do you have a best grocery store to find that one special item? What are your grocery shopping hacks and pro moves? Share your special finds and stellar victories in the comments.