How to Check a Product’s Price History: 10 Steps Before You Buy

Before you look anything up, find the precise model number or product ID: not “Sony headphones,” but the full code. Colors, storage sizes and bundles often have separate price histories, and some products have near-identical twins sold under different model numbers at different stores, a common trick around big sales (see our Black Friday rules).

Look in the product’s specifications on the store page, on the box or on the label of the device itself. On Amazon, the ASIN, a 10-character code in the product details, identifies a specific listing, and it’s what most Amazon price trackers use.

A two-week chart shows noise. A 90-day chart shows the usual price. A one-year chart shows the seasons: the predictable dips around big sale events and the slow slide as a model gets older. If you can see a year, you’ll know what “low” really looks like for this product.

Three shapes are worth recognizing:

• A flat line with occasional dips: a stable product with periodic sales. Wait for the next dip.
• A staircase going down: an aging model being cleared out. Waiting usually pays, until stock runs out.
• A sawtooth that jumps up just before sales: see step 7.

For Amazon, two long-running tools do the heavy lifting. CamelCamelCamel is a free website that charts prices for Amazon itself and for third-party sellers’ new and used offers. Keepa draws similar charts and offers a browser extension that shows the history right on the Amazon product page; much of it is free, and some features need a subscription.

When you read the chart, find the line for the seller you’d actually buy from. The line for Amazon as the seller is usually the steadiest. Third-party lines jump around as sellers come and go, and a cheap price from a seller you’d never buy from isn’t your price.

For products sold by many stores, Google Shopping is a quick way to compare. For many products, Google shows price insights such as a typical price range and, for some items, a price history, and it lets you track a product to get an email when the price drops. What you see depends on the product and the country, so treat it as one data point, not the last word.

It’s also the fastest way to spot a store charging well above the rest, or a “deal” that’s simply the going rate everywhere.

Tap or hover over the small “i,” or the explanation link, next to a crossed-out price. Many big retailers say what their reference price means: a recent typical price, a manufacturer’s list price, or the lowest price over a set period. Those definitions matter. A list price may be a number almost nobody pays, while a typical price based on recent sales is far more useful.

In the European Union, shops announcing a price reduction must show the lowest price they charged in the previous 30 days. Even if you shop elsewhere, that’s a smart rule to borrow: compare today’s price with the recent low, not with the biggest number on the page.

Use the chart to pick a price you’d be happy to pay, for example the lowest price of the past six months, or a few percent above the lowest price of the past year. Write it down. A target turns “Is this a deal?” into a yes-or-no question, and it protects you from the “biggest sale ever” banner.

Be realistic. If an item hit its all-time low once, for a few hours during a major event, don’t build your target around that blip.

Some sellers nudge a price up in the weeks before a sale event, then “cut” it back to roughly where it was. On a chart, that’s a bump followed by a drop to the old level, and the discount badge is calculated from the bump.

On marketplaces, the same product page can be filled by different sellers at different times. A lower price may come from a third-party seller with slower shipping, a shorter return window or no clear warranty. Before you jump, check the “sold by” and “ships from” details, the return policy and the seller’s ratings. A few dollars saved isn’t worth a product you can’t return.

You don’t have to check prices every day. CamelCamelCamel and Keepa can email you when an Amazon price falls below your target. Google can tell you when a tracked product gets cheaper. Many store apps alert you when wish-list items go on sale, and deal communities such as Slickdeals let you set keyword alerts.

Set alerts at your target prices, then ignore the item until one of them fires.

Price tracking is meant to save money, not to win a game. Buy when:

• the price is at or within a few percent of your target;
• the item is being discontinued and stock is thinning, since prices can jump rather than drop;
• you need it now, and the likely saving from waiting is smaller than the cost of going without.

After you buy, check whether the store offers a price adjustment if the price drops within a set period. Some do, many don’t, and policies change, so read the current terms.