How to tell a real discount from a decorated one

Arbi guide · Last updated 24 August 2026 · about 5 minutes to read

A discount is a claim about the past: this used to cost more. You cannot verify the past from a product page. But you can test the claim, and it takes about a minute.

Six checks, in order of usefulness

Compare the final price, not the percentage. The only number that leaves your bank account is the total. Two shops, two totals — that comparison cannot be dressed up.
Add delivery before you compare. A £12 saving disappears against £4.99 delivery plus a £40 free-delivery threshold you would have cleared elsewhere.
Check whether the price includes something you would have to buy anyway. Bundles are a legitimate way to make a comparison impossible. If one shop includes filters, pods or a case, the like-for-like has changed.
Look at how long the offer has run. A countdown that resets every time you reload is not a deadline.
Check the model number, not the name. Last year's model at a genuine 30% off is a real saving. This year's model at a fake 30% off is not. They often share almost the same name.
Ask what the price was a month ago. If you cannot find out, treat the discount as unproven rather than false.

The trap that catches careful people

The most effective misleading discount is not a lie about the old price. It is a change of product. A retailer-exclusive variant with a slightly different model code is genuinely cheaper — and genuinely not the same thing. It may have a shorter warranty, fewer accessories, or different specifications.

This is legal, common, and completely invisible if you compare on product name alone.

The one thing to do: copy the model number out of the product page and search that instead of the product name. If the model numbers do not match across two shops, you are not comparing two prices — you are comparing two products.

What a good saving actually looks like

Real savings are usually unremarkable. The same exact model, at a price two or three shops agree is normal, from one shop that happens to be £20 or £40 under the others this week. No countdown, no dramatic percentage, no bundle.

The offers that look most exciting are the ones most worth checking.

Seasonal sales are the hardest to read

Black Friday, January sales and mid-season events are when reference prices are most stretched, because everything is discounted from something and nobody is comparing carefully. Two habits help:

Decide what you want before the sale starts, and note the price then. Deciding during a sale means the sale decides.
Check the same item at two shops that are not running the same event. If everyone's sale price lands within a few pounds of each other, that is the actual market price, and the “discount” is scenery.

What Arbi does about it

Arbi never shows a price it has not read from a real page, never claims a discount is genuine, and shows the retailer's own previous price as the retailer's claim rather than as fact. Where it can, it compares the cheapest option against the next cheapest rather than the most expensive — because “£80 less than the next cheapest” is a number you can check, and “£300 off” usually is not.