The Price-Per-Use Rule: How to Know if a Purchase Is Worth It

The Simplest Rule for Better Spending Decisions

Every purchase has two prices: the sticker price and the price per use. The sticker price is what you see. The price per use is what it actually costs you.

The rule: Before buying anything non-essential, estimate how many times you'll use it. Divide the price by that number. If the price per use feels reasonable — buy it confidently. If not — skip it.

Price Per Use in Action

Suddenly, the "expensive" jacket is a better deal than the "cheap" kitchen gadget.

Why This Rule Works

It shifts focus from price to value

A €15 t-shirt that falls apart after 5 washes costs €3/wear. A €45 t-shirt that lasts 100 washes costs €0.45/wear. The "expensive" shirt is 6x cheaper.

This is the core of buy it for life thinking — paying more upfront for things that cost less over time.

It kills impulse purchases

The mental exercise of estimating future usage introduces a pause. That 3-second pause is usually enough to stop a bad impulse buy. If you can't imagine using something 20+ times, it's probably not worth buying.

It justifies quality purchases

Feeling guilty about buying something expensive? Do the math. If a €800 mattress lasts 8 years (2,920 nights), that's €0.27/night. For something you spend a third of your life on, that's incredible value.

Price Per Use Categories

Almost always worth it (low price per use)

• Daily wear basics — good shoes, quality jeans, a reliable bag
• Technology you use daily — phone, laptop, headphones
• Kitchen essentials — good knife, cast iron pan, quality blender
• Health investments — good mattress, running shoes, water filter
• Tools you'll use for years — not gadgets, actual tools

Rarely worth it (high price per use)

• Trendy clothing — worn 2-3 times before the trend passes
• Single-purpose kitchen gadgets — waffle maker, pasta machine, spiralizer
• Event-specific purchases — decorations, theme costumes, specialty gear for a hobby you might drop
• The "just in case" purchase — items bought for hypothetical future scenarios

The gray area (do the math)

• Gym membership — €50/month is €1.67/day if you go daily, or €12.50/visit if you go once a week. Honest usage determines the value.
• Streaming subscriptions — €14/month ÷ hours watched. If you watch 20 hours/month = €0.70/hour (great). If 2 hours/month = €7/hour (expensive entertainment).
• Car ownership — total cost (payment + insurance + fuel + maintenance) ÷ kilometers driven. Sometimes Uber is actually cheaper per trip.

How to Apply This Today

Before buying online

Add to cart. Wait 24 hours. If you still want it, estimate price per use before clicking "buy."

In a store

Pick it up. Ask: "How many times will I actually use this?" Be honest. If the answer is "maybe once or twice" — put it back.

For subscriptions

Monthly cost ÷ monthly usage. Any subscription you use less than once a week is probably not worth a monthly fee.

For big purchases

This is where price per use really shines. A €2,000 sofa you'll sit on every day for 10 years? €0.55/day. A €500 camping setup you use twice a year? €25/trip — still potentially worth it if those trips are meaningful.

The Exception: Experiences

Price per use works less well for experiences — concerts, travel, unique events. A €200 concert ticket has a "price per use" of €200 (one show). But the memory, the emotion, the story might be worth far more than something you'd use 100 times.

For experiences, ask instead: "Will I still value this memory in 5 years?" If yes, it's worth it regardless of the math.

Track What You Actually Use

The price-per-use calculation is only as good as your estimate of future usage. Most people are overly optimistic — "I'll definitely use this 3 times a week!" (Reality: twice, then it sits in a drawer.)

Portofelo helps you see your actual spending patterns. When you track where your money goes, you start seeing which purchases turned out to be high-value and which were waste. That data makes your future estimates more honest — and your spending decisions sharper.