How to Read a Price History Chart Before You Buy

"30% off" tells you nothing on its own. It only means something once you know what it's 30% off of, and that regular price is set by the retailer, not by what the item has actually sold for in the past. A price history chart replaces that one number with the item's full sale history, so you're comparing today's price against reality instead of a sticker.

ShelfAware logs a product's price every time it changes, which builds a line you can scan for two things: the all-time low (the cheapest that item has ever sold for) and how often the price moves. An item that's barely moved in months and just dropped to a new low is a genuinely rare deal. An item that swings up and down regularly, including a jump right before the current "sale," is worth more skepticism.

If today's price matches or beats the all-time low, that's about as close to a guarantee as pricing gets. If it's higher than a price the same item already hit a few months ago, the current discount is smaller than it looks, no matter what the tag says.

• Find the lowest point on the chart first.That's your baseline for whether the current price is actually good.
• Check how recent that low was. A low from a year ago matters less than one from last month, since prices and availability both drift over time.
• Set an alert at or near the all-time low.Rather than watching the chart yourself, a target price alert tells you the moment it's hit again.

Every product on ShelfAware has a full price history chart, free, with no account required to view it. Search a product to see its chart and all-time low before you buy.