How can you tell if the Black Friday laptop really dropped in price?

Three common ways a laptop can look cheaper than it is: the price goes up in the days before Black Friday and returns to normal with a "discount" label; the crossed-out "was" price is a value the laptop never really had; and the ad compares one version with another of the same name, like the 8 GB of RAM one with the 16 GB one. None of them shows up if you only look at the store page on the day.

What takes all three apart is the price history: the price of the same laptop, in the same version and from the same seller, day after day.

The Radar records the price of each laptop every day. To decide whether a drop is real, it compares today’s price with the median of the last 30 days from its own price history, from the same seller. The median is the middle value, so a price spike the day before doesn’t pull it up. The math:

drop = (30-day median − today’s price) ÷ 30-day median

Only what stays below of that median is called a discount. The store’s crossed-out price doesn’t enter the math. A change of seller doesn’t count as a drop either, because it’s a different price, from a different place.

To confirm a discount, the laptop needs at least 14 days of its own history on the Radar. Before that, the page shows today’s price and a note that the 30-day median is still being built, without the word "discount". The same goes for the "find" label and for the list of laptops that dropped in price.

That means that near Black Friday, the list may be shorter than the advertised deals. That’s on purpose: we’d rather show little that’s true than a lot that’s doubtful.

The same model is often sold in several versions, with different RAM and SSD, and the name barely changes. A "discount" that compares the price of one version with another isn’t a discount. The Radar shows the RAM and SSD of each version next to the price.

Before buying, check in the specs: the model number, the amount of RAM, the SSD size and the processor. If any of them differs from what you saw before, it’s a different product.

1. Find the laptop’s page. Each model has its own, with the price chart and the verdict of the day.
2. Look at the chart line, not the store’s badge. Is today’s price below the line of the last 30 days?
3. Confirm the full version. The model number, RAM, SSD and processor all count: the 8 GB and the 16 GB with the same name are different products, with different prices.
4. Check the seller. A price from an unknown seller isn’t worth comparing; the Radar only uses trusted sellers.
5. See the final price at the store. Shipping, delivery time and warranty change the math, and the final price is the one at the store.

Each list shows the collection date and hides anything that doesn’t have enough history yet.