Why the Same Product Costs Different Prices at Different Stores - The Hidden Logic of Pricing

Take a 500ml bottle of water as an example. The exact same product from the exact same manufacturer costs wildly different amounts depending on where you buy it.

Supermarket sale: 68 yen. Drugstore: 78 yen. Convenience store: 110 yen. Vending machine: 130 yen. Train station kiosk: 140 yen. Movie theater concession stand: 200 yen. Theme park: 250 yen.

The gap between the cheapest and most expensive is 3.7x. The water inside is identical. The explanation comes down to two factors: "location costs" and "the price of convenience." As covered in the true cost of bottled water, the water itself costs just 1-2 yen to produce. Everything else - the bottle, transportation, store rent, labor, and profit - accounts for the rest.

Writing the gap off as store greed ends the conversation too early. It is worth following what happens to that bottle before it gets a price tag, because each step adds a different amount.

The first place a gap appears is the size of the order. A store that takes delivery of a full truckload pays a very different amount per bottle than one that receives a handful mixed in with everything else. The cost of driving that truck is the same either way, so it gets divided by however many bottles were on it. Order in bulk and the share each bottle carries shrinks; take small amounts and it grows.

The second is delivery frequency. A small sales floor has nowhere to store stock, so it accepts deliveries several times a day. That keeps the shelves from going empty, which is the whole point - but every one of those trips costs something, and the cost has to land somewhere. A store with a stockroom can absorb the same volume in far fewer trips.

The third is the sales floor itself: rent, electricity, and the wages of the people standing in it. These get divided by the number of items sold, so the more a store sells, the lighter the burden each bottle carries. On a product whose contents cost only 1 to 2 yen, as covered in the real cost of bottled water, that denominator is essentially the entire price difference.

So the gap is not a markup a store tacked on after the fact. It falls out of how that store sells. Which means that two stores in different formats arriving at different prices for identical goods is the expected outcome, not an anomaly.

Supermarkets and drugstores keep prices low through a strategy called high-volume, low-margin selling. They accept a tiny profit on each item and make up for it by selling enormous quantities.

For example, if the profit on one bottle of water is 5 yen but the store sells 500 bottles a day, that's 2,500 yen in daily profit. A convenience store might earn 30 yen per bottle but sell only 50 a day, netting just 1,500 yen. Lining up the per-bottle margins alone tells you nothing about which store is doing better.

For a store built this way, cutting the price is itself the tool that brings customers in. A store that cannot grow its customer count would run out of daily profit at the same price and could not stay open.

As explained in why drugstore groceries are cheap, drugstores deliberately sell food and beverages as loss leaders - products priced at or below cost to draw customers into the store, where they then buy higher-margin items like medicine and cosmetics. Behind every low price, there's always a reason it can be low.

Convenience stores and vending machines charge more because the cost of "convenience" is baked into the price. A convenience store stays open 24 hours and sits within a few minutes' walk of almost anywhere. Maintaining that accessibility requires late-night labor costs, premium rent near train stations, and frequent small-lot deliveries.

As discussed in the economics of vending machines, the price premium on a vending machine reflects the value of "right here, right now." When you're thirsty, do you walk 10 minutes to a supermarket to save 40 yen, or pay 130 yen at the machine in front of you? Most people choose the latter.

Movie theaters and theme parks charge the highest prices because they operate in a near-monopoly. You can't bring your own drinks into the theater - and that rule exists partly to protect the monopoly pricing. When there's no competition within arm's reach, the seller sets the price.

So far this has been about differences between store formats, but prices do not always match within a single chain either. Inside the ticket gates at a station, at an airport, at a highway rest stop, across from a tourist landmark - the same signage can sit above a higher shelf price.

The reason is the one from the previous section. Putting a store in those places costs more. Rent where foot traffic is heaviest is high, and there are often limits on operating hours and on how deliveries can get in. The floor space is small, so the range of goods is narrow. Making the numbers work under those conditions leaves price as the only lever.

From the customer's side this is a hard difference to spot. Matching signage suggests matching prices, so you pick the item up and find out at the register. It helps to think of it as the same location effect described in the economics of vending machines, showing up inside a chain rather than between formats.

The practical takeaway is a rule of thumb: a store that sits along your route may be charging for that convenience. Buy it inside the gates, or step outside first. Those few minutes can be sitting in the price tag - worth a glance at the shelf on the days you are not in a hurry.

Hunting for the cheaper store is not automatically correct. Getting this backwards is how people lose money while believing they are saving it.

What the price gap has to be weighed against is the time and the fare it takes to reach it. Walking 20 minutes round trip to save 40 yen means giving up whatever those 20 minutes were worth. Take a bus to get there and the fare erases the saving outright. Traveling to a distant store for a single bottle of water rarely adds up.

Buying cheaply and then not using it up has the same shape. Bulk buying lowers the unit price in exchange for a larger pile sitting at home. If it expires before you drink it, or you run out of space and throw some out, the money spent is gone in full. A low price only means something within the amount you can actually finish.

Convenience stores and vending machines really are expensive, but what that price buys is having the thing in your hand right now. Going without water in dangerous heat, arriving late to something that mattered, ending up unwell - if the price avoids those, 130 yen is not expensive. The point of understanding seller tactics like loss leaders is not to lock yourself into the cheapest store, but to be the one deciding which trade-off you want today.

Once you understand that the same product costs different amounts at different stores, you can save money simply by being intentional about where you shop. Three rules cover the basics.

Rule 1: Buy planned purchases at supermarkets or drugstores. Build a habit of doing a weekly grocery run, and the savings over convenience store prices add up fast. If you buy 20 drinks a month, the gap between supermarket prices (68 yen) and convenience store prices (110 yen) is 840 yen per month - roughly 10,000 yen per year.

Rule 2: Carry a reusable bottle. Brew tea at home and bring it in a bottle, and your beverage cost drops to nearly zero. One tea bag (about 5 yen) makes 500ml of tea. Compared to 130 yen at a vending machine, that's a 125 yen saving every single time.

Rule 3: Minimize "emergency" purchases. Reserve convenience stores and vending machines for moments when you truly need something right now. A little advance preparation means you avoid paying the premium for instant access.

If you do end up at a convenience store, knowing convenience store markdown strategies helps you spot discounted items and keep spending in check.