Is it worth it? The cost-per-use check

An expensive coat worn two hundred times is cheaper than a bargain worn twice. Cost per use is a simple way to cool down before buying — and AI will do the sums and ask the uncomfortable questions you would rather skip.

Use the same trick for subscriptions and memberships: “I pay this much for the gym and went four times last month”. Seeing the price of each visit usually makes the decision for you — in either direction.

Why price is the wrong number

The price of something tells you what it costs to own. It does not tell you what it costs to use, and use is what you are actually buying. A 200 coat worn 150 times costs just over 1.30 a wear. A 60 dress worn once costs 60. The cheaper item was by far the more expensive one. Cost per use is a simple idea that corrects two opposite mistakes at once: wasting money on bargains you never use, and denying yourself well-made things that would have paid for themselves.

The sum

Divide the price by the number of times you will realistically use the thing. Then add any running costs: coffee beans, filters, electricity, membership fees, repairs. Finally, compare the result with what you do now, or with the cost of renting or borrowing. That is all. AI is helpful because it does the sum quickly, asks what you have forgotten and, most usefully, challenges your estimate of how often you will use it.

A worked example

You are looking at a 350 coffee machine. You currently buy a coffee on the way to work, four days a week, for about 3.50.

AI works it out. Four coffees a week is about 14, or roughly 700 a year. At home, beans and milk might cost around 0.50 a cup, or about 100 a year for the same number of coffees. So the machine saves around 600 a year in running terms and pays for itself in about seven months, if you really do stop buying coffee out. Then it asks the honest question: will you? If you would still buy one or two a week because you enjoy the walk and the cafe, the saving halves and the payback period doubles. It may also suggest a cheaper route to the same result, such as a simple cafetiere for 20.

Be honest about how often

1. 1

   Count past behaviour, not future intentions

   How often did you use the last similar thing you bought? That is the best predictor.

2. 2

   Halve your first estimate

   People consistently overestimate how often they will use exercise equipment, kitchen gadgets and hobby gear.

3. 3

   Consider the season

   A bicycle used daily in summer may sit for five months of winter.

4. 4

   Think about the effort

   If using it requires setting up, cleaning or travelling, you will use it less than you think.

5. 5

   Check where it will live

   Things stored in a cupboard are used less than things on the counter.

Costs people forget

• Running costs: refills, cartridges, pods, electricity, fuel.
• Maintenance: servicing, descaling, replacement parts, batteries.
• Accessories you will need to make it useful.
• Space: storing something large has a cost, even if you do not pay it in money.
• Insurance or subscription fees attached to the product.
• What it will be worth second-hand, which reduces the true cost if you resell it.

Follow-up prompts

• “Compare buying this with renting or borrowing it, given I would use it [number] times a year.”
• “What would a good second-hand version cost, and how does that change the cost per use?”
• “List the running costs of owning a [item] over five years.”
• “I am choosing between a cheap version at [price] that might last [years] and a better one at [price] that might last [years]. Compare cost per year.”
• “Ask me five questions to test whether I will really use this as often as I think.”
• “Work out the cost per use of things I already own: [list with prices and rough use]. Which were my best and worst purchases?”

Where it works especially well

Cost per use is most revealing for clothes and shoes, where a good pair worn for years beats three cheap pairs. For kitchen appliances, where the test is whether it earns its place on the counter. For gym memberships and exercise equipment, where real attendance is the only number that matters. For tools, where anything you need once a year is nearly always better hired or borrowed. And for subscriptions, where dividing the monthly price by the number of times you actually opened the app can be sobering.

What the number leaves out

Not everything should be judged per use. A fire extinguisher has, you hope, a very poor cost per use and is still worth owning. A wedding outfit is worn once on purpose. A musical instrument brings joy that a spreadsheet does not measure. Safety, pleasure and meaning are legitimate reasons to buy something. The point of the calculation is not to stop you spending. It is to make sure you are choosing with your eyes open.

Remember too that AI’s figures are estimates. It does not know local prices, how long a particular product lasts or what energy costs where you live. Put in your own numbers wherever you can, and treat the result as a rough guide.

The 30-day pause

For anything that is not urgent, combine the calculation with a waiting period. Put the item on a list with today’s date and the cost per use you worked out. If you still want it in thirty days and the sum still makes sense, buy it without guilt. A surprising number of items lose their appeal within a week, which costs nothing and saves the full price.

Common mistakes

• Using the number of times you hope to use it.
• Ignoring running costs, which sometimes exceed the purchase price.
• Buying the cheapest version of something you use daily.
• Buying the expensive version of something you will use twice.
• Forgetting that the alternative might be “nothing”, which is free.

Quick questions

1. 1

   What is a good cost per use?

   There is no fixed figure. Compare it with what the alternative costs and with what the use is worth to you.

2. 2

   Does this work for experiences?

   Not really. A holiday is not a per-use purchase. Ask instead whether it fits your budget and priorities.

3. 3

   Should I include resale value?

   Yes, if you would really sell it. Subtract a realistic resale price from the cost.