Most sales in British retail are theatre: the sofa was never really £1,199, and the air fryer has spent more weeks at £89 than at its supposed usual price of £129. The 'was' price is doing the heavy lifting in almost every discount you see, and the retailer is betting you have no memory. The fix costs nothing — a handful of free tools that remember every price so you don't have to.

Which? has made a ritual of checking Black Friday deals against the rest of the year, and the finding repeats annually: the overwhelming majority of headline deals were available at the same price or cheaper at some other point in the year. That's not a scandal exactly. It's just how was-pricing works — and it means the single most valuable shopping skill in 2026 is checking the graph before believing the sticker.

Amazon: CamelCamelCamel and Keepa

Amazon changes prices constantly — sometimes several times a day — which makes it both the worst place to trust a discount and the best place to exploit one. Two free tools cover it:

  • CamelCamelCamel (camelcamelcamel.com) shows the full price history of any Amazon product — paste the URL, get the graph. The graph tells you instantly whether today's 'deal' is the product's normal floor, a genuine dip, or a markup dressed as a markdown. You can set a target price and get an email when it drops there.
  • Keepa does the same job as a browser extension, drawing the history chart directly onto the Amazon product page, plus tracking third-party seller prices. For anyone who buys from Amazon more than occasionally, it removes the guesswork permanently.

What the graphs teach you within a week of using them: 'Limited time deal' badges frequently sit on ordinary prices, and most products cycle predictably. The £40 thing you want has probably been £31 twice in the past six months and will be again. The alert means you buy it then — without checking, hoping, or caring what day of November it is.

Everything else: Idealo, PriceSpy, PriceRunner

Off Amazon, three comparison sites do the same work across UK retailers:

  • Idealo compares prices across hundreds of shops and keeps price histories, so you can see whether Currys' 'save £70' reflects reality anywhere.
  • PriceSpy is particularly strong on electronics and shows each retailer's price history separately — useful for spotting the shop that quietly inflated before discounting.
  • PriceRunner covers similar ground with UK stock and alerting.

All three are free, all three offer price alerts, and between them they cover most of what a household buys deliberately: appliances, tech, tools, kids' gear. The workflow is dull and effective — find the exact model number, set an alert at the price you'd genuinely pay, close the tab. Bare-minimum effort, and it converts you from someone retailers advertise at into someone who buys at the bottom of the cycle.

The graph changes your behaviour, not just your price

Something happens when you start looking at price histories: the urgency dies. Sale countdowns, 'only 3 left', one-day events — the entire apparatus of retail pressure works on the premise that this price is fleeting. The graph shows you it isn't. Prices cycle; the same dip returns.

That pairs naturally with the oldest trick in the book, the 30-day rule: for any non-essential purchase over, say, £50, set the alert and wait a month. One of three things happens — the price drops and you buy well, the urge passes and you save 100%, or the urge survives and you buy a considered thing at a known-fair price. There is no fourth outcome where waiting cost you anything that matters.

A few habits complete the kit:

  • Search by exact model number, not product name. Retailers sell near-identical variant models precisely to frustrate comparison — the graph for the wrong variant tells you nothing.
  • Beware Black Friday exclusives. Derivative models made for the sales event have no price history at all, which is the point.
  • Check refurbished before new once you know the fair price — a certified refurb at 30% off a genuine price beats 20% off a theatrical one.
  • Screenshot the graph if you're claiming a price-match; a documented lower price elsewhere is exactly what Currys' and John Lewis's match policies exist for.

What this is actually worth

On groceries, loyalty schemes and yellow stickers do the work. But on the £80–£600 purchases — the washing machine, the phone, the winter coat, the laptop — buying at the documented low rather than the advertised 'sale' is routinely worth 15–30%. A household making four or five such purchases a year quietly banks £100–£300, in exchange for pasting a URL into a free website and possessing a little patience.

The retailer's advantage has always been that it remembers every price and you remember none. The tools flip that — and once you've seen the graph, you can't unsee it. The air fryer was £89 all along.