How to check price history before you buy

Verdict: Check first, then decide. A two-minute look at the price history beats any banner, countdown or "was" price.

You can check price history for almost any product sold online. The goal is not to find the perfect day. The goal is to learn what "usual" looks like, so a sale has something to be compared with.

Sale dates and prices change every year. Always check the retailer for the current offer.

How do you check price history on a product?

Use the price-history check. It has three steps.

1. Last 30 days. Is the price already near its low? If it was lower last week, today is not a record.
2. Last 90 days. Has it been this price before? How long did it stay there? A price that appears for weeks is the normal price.
3. Last big event. Look at the same product during the last major sale season. If the event price was lower, you may want to wait for the next one.

Where do you see this data? Some stores show a price chart on the product page. Free browser add-ons and price tracker sites also keep charts for popular products. Features and coverage differ, so use the tool that works for the store you are on. Not every product has a long history, especially new ones.

How do you read a price chart?

You only need to look for three shapes.

• A flat line. The price barely moves. A sale banner on a flat line is a normal price. Skip the sale.
• A line with regular dips. The price drops and comes back. Note how deep the dips are and how often. Wait for the next dip if the current one is shallow.
• A line that rises, then drops back. This can mean the price was raised before the event. If the drop only returns it to the old level, there is no saving.

A worked example

These numbers are round and made up to show the method. A vacuum cleaner shows a "was" price of $200 and a sale price of $150. Your chart shows $150 for most of the last 90 days, with a dip to $130 during last year's big event. The "50 off" is not a discount. It is the usual price. The $130 dip is the real low. Your ruling: wait for the next event, or buy now only if you need it.

What is a target price, and how do you set one?

A target price is the number you decide to pay before you see any sale. Set it from the chart. A good start is the lowest price in the last 90 days, or the last event price if it is lower. Then you have a rule: buy at or below the number, wait above it.

Write it down. A target on paper stops the "it is only a little more" slide that turns a plan into an impulse buy. Some price trackers let you set an alert so you do not have to check by hand.

The target can be too low. If you set a number the product never reaches, you will wait forever. Review it after a few weeks. If the lowest price you have seen is steady, move your target to it.

When does price history not help?

Price history is weak or useless in a few cases.

• New products. There is no past to compare. Prices on new models tend to stay put for a while.
• Clearance and last-unit stock. The price falls as stock runs out, and the history stops when the item does.
• Marketplace sellers. One listing can have many sellers, and the chart may mix them. Check who sells the item and who ships it.
• Bundles and variants. A bundle with extras can look like a lower price. Compare what is in the box, not just the number.

If the chart looks odd, trust the pattern across stores. Check the same product at two other stores. If they all sit near the same number, that is probably the real price.

What if the price is good but the history is short?

Use the category pattern as a stand-in. Many products follow predictable cycles, such as TVs in the fall or coats in winter. The best time to buy 10 common things lists the usual windows. Combine the pattern with a target price, and a short history matters less.

Common mistakes

• Trusting the struck-through "was" price instead of the chart.
• Checking only one store.
• Checking the chart once and never again. Prices move.
• Ignoring the return window. A low price with a short window is risky, so read returns and price adjustments before you pay.
• Treating a "lowest price" label as proof. Labels depend on how far back the tool looks.

How often should you check?

For a planned purchase, look once a week. For a seasonal item, look every few days as the window nears. Set an alert if the tool offers one, so you do not have to remember. Stop checking once you have bought. A price that drops after you buy is covered by the store's adjustment policy if it has one, so read returns and price adjustments before you pay.

A quick ruling

Check often enough to catch a dip, not so often that it becomes a habit. Weekly is plenty for most things.