The UK shop gap: same part, different price

How we work it out

• We read prices from UK retailers every day. This report uses only the prices our product pages show.
• A price counts if it is for new stock, the shop says it is in stock, and we checked it in the last 14 days. Refurbished, open-box and used listings are left out.
• Each shop counts once per part, at its lowest price. A part needs prices from at least 3 different shops to be included.
• Any listing our checks say may be a different model or version (a different memory size, board range or model code in the shop's own listing) is left out. On top of that, every shop's link has to name the same model number as our page, or the whole part is left out, so a gap is always between listings for the exact same product.
• The gap is the dearest price minus the cheapest. Parts where the dearest price is more than 50% above the cheapest are left out: when we checked those by hand, most were listing errors rather than real prices.
• We use the median, the middle value, so a handful of extreme listings cannot pull the typical figure up.
• Prices are before delivery and change every day. The figures here are rebuilt once a day.