How do I compare prices properly?

Price comparison is mostly about making sure you're comparing the same thing. Different pack sizes, different contract lengths, different inclusions and different running costs all mean the headline numbers are rarely directly comparable.

Step by step

1. Reduce everything to the same unit before comparing.Price per kg, per litre, per 100g, per month. Shelf labels show this in small print; use it.
2. For anything with running costs, calculate total cost of ownership.Purchase price plus energy, consumables, servicing and expected lifespan. A cheaper appliance that costs more to run is not cheaper.
3. For contracts, work out the total over the full term.Monthly price times the contract length, plus any upfront cost and any post-term price increase.
4. Check what's actually included in each option.Delivery, installation, warranty, consumables. Exclusions are how a headline price gets lowered.
5. Check price history before believing a discount.Browser extensions and price-tracking sites show whether the 'was' price was ever real or was set briefly to enable the claim.
6. Factor in the cost of returning it if it's wrong.Free returns have genuine value, particularly for anything you can't assess without receiving it.
7. Set a decision deadline in advance.Open-ended comparison costs time that eventually exceeds the saving. Decide how long the decision is worth.
8. Sleep on anything significant.Urgency is a sales technique. Genuinely good prices are rarely available for only twenty minutes.

Tips

• Cheaper per unit isn't better if you won't use it all. Bulk pricing only applies if the whole quantity gets used.
• Comparison sites don't all cover the whole market and many are paid by the products they list. Cross-check at least two, and check direct with the provider.
• For expensive items, the reliability and lifespan matter more than the price difference. A product lasting twice as long at 50% more is cheaper.
• Write down your criteria before you start looking. It's much harder to be talked into the wrong thing when you've defined what matters in advance.

Common mistakes

• Comparing pack price rather than unit price — Different pack sizes make headline prices meaningless.
• Ignoring running costs — For appliances, vehicles and anything with consumables, running cost usually exceeds purchase price over the lifespan.
• Trusting the 'was' price — Reference prices are often brief or nominal. Check the actual price history.
• Comparing forever — The time spent eventually exceeds the saving. Set a deadline in advance.

Questions people ask