Where comparing prices pays, and where it wastes your time
We measured 86 products across ten categories — the gap is not spread evenly
The advice "compare prices" is true and useless, because it does not say on what. So we measured: 86 products, ten categories, a median price per chain. The result is concentrated in very particular places.
How we measured — and what it is worth
For each product we took the median price in each chain, only for chains with five or more branches, and only for products sold in at least four such chains. That stops a one-off promotion in a single shop from inflating the result.
The median gap across all products: 1.32× between the cheapest and dearest chain. In 63% of products the gap is 25% or more, and in 30% it is 50% or more. Worth saying plainly: this is a sample of 86 products, not a census — enough to point at a direction, not to fix an exact number per category.
The categories where comparing returns most
Sweets and chocolate led with a median gap of 1.59× (8 products). Then personal care and pharmacy at 1.44× (13 products), household goods at 1.39× (14 products), and snacks at 1.39× (5 products).
What they share: these are products nobody remembers the price of. There is no "right price" sitting in your head, so nothing pushes the chains to line up.
And where there is barely anything to check
Bread and bakery closed the list at 1.15× (9 products), with cereals at 1.17× (11 products) and dairy at 1.17× (only 4 products — a small sample, treat it as indicative).
That makes sense too: these are bought weekly and their price is familiar. A chain pricing bread 40% above the market would hear about it immediately, so it does not.
Five real products from the measurement
Cotton buds (tub of 500) — ₪2.70 at Osher Ad against ₪7.90 at Super Yuda, 2.93× across 15 chains. The largest gap we measured.
A 500g bag of ptitim — ₪5.50 at Yochananof against ₪10.90 at Super Yuda, 1.98× across 27 chains. Spray deodorant — ₪9.90 at Good Pharm against ₪18.90 at King Store, 1.91×.
Shaving gel — ₪14.90 at Kol Bo Hatzi Hinam against ₪23.90 at Tiv Taam, 1.60× across 20 chains. Honey Bunches cereal — ₪17.90 at Yochananof against ₪27.90 at Shufersal Express, 1.56×.
The practical rule
Do not compare the whole trolley. Compare the non-food aisles — personal care, cleaning, pharmacy — and the sweets. That is where the gap is large, and it comes back every shop.
Bread, milk and eggs you can buy wherever is convenient. The gap there is too small to justify even the check, and that is exactly the time worth spending elsewhere.