The cheapest price is rarely the cheapest cost
Price comparison has an old blind spot. It compares the number on the product page, and you pay the number at the checkout. Those are different numbers, and the gap is where a good deal quietly becomes a bad one.
What sits between the two
| Cost | Typical size | How it hides |
|---|---|---|
| Standard delivery | £3–£6 | Shown at checkout, after you have decided |
| Large-item or two-person delivery | £20–£60 | Often only revealed once a postcode is entered |
| Free-delivery threshold | Varies | “Free over £50” is not free delivery if you are spending £38 |
| Return postage | £3–£15 | Only matters if you send it back — which is exactly when you are least happy |
| Installation or removal | £20–£40 | Appliances especially. Some shops include it, some charge for it |
A worked example
Shop A: £299, delivery £4.99. Shop B: £305, free delivery over £50. Shop A looks £6 cheaper and is actually £1 dearer. On a fridge, where one shop charges £30 for delivery and another includes it, the “cheapest” shop can be £25 more expensive.
Returns are a cost even when you don't use them
For anything you might send back — clothing, shoes, anything sized, anything you have not seen — free returns are worth real money. A shop that is £10 cheaper but charges £8 to return is only cheaper if you keep it.
Under UK consumer law you generally have 14 days to change your mind on something bought online, and 14 days after that to send it back. But who pays the return postage is up to the retailer unless the item is faulty. That is the detail worth checking before you buy, not after.
Click and collect is often the honest cheapest
Collection is free at most large UK retailers, and it removes the two costs that distort comparisons most: delivery and failed deliveries. It also lets you check the item before it goes in the car. On anything bulky, or anything where you would rather not spend a Tuesday waiting in, collection frequently beats the cheapest online price outright.
The catch is that collection availability is per-store and per-item, so it will not show on a comparison. It is worth one check on the shop that is second-cheapest — that is where collection most often flips the answer.
The postcode problem
If you live in the Scottish Highlands, Northern Ireland, the Isle of Man or the Channel Islands, a large number of “free UK delivery” offers quietly do not apply to you, and surcharges of £15–£50 are common on bulky goods. The surcharge almost never appears on the product page. Enter your real postcode early rather than at the end.
What Arbi does about it
Where a shop states its delivery cost clearly enough to be read, Arbi adds it and shows a cost to home rather than just a price. Where the shop does not state it — or states it conditionally, as in “free over £40” — Arbi says delivery: check rather than guessing. An unknown delivery cost quietly treated as zero is exactly how a comparison tool misleads people, so Arbi refuses to do it.