How great are Black Friday sales? Sure, they look great when you see an item is discounted by 30%, but retailers often use a trick to make shoppers believe the price cuts are better than they actually are.

I set out to research which gadgets will likely be on big discounts on Black Friday and Cyber Monday and I discovered something that Amazon and many other retailers do to make it seem like products are a great deal. More on that in a few minutes.

I searched for discounts on popular tech gadgets and what we might expect on Black Friday weekend. Amazon products typically hit their lowest prices of the year on Black Friday, Cyber Monday, and Amazon Prime Days.

The Kindle Paperwhite, which is $149 now, typically drops to around $99 on the shopping holidays. There is a better time to buy one if you can wait a few days. I used the website www.camelcamelcamel.com which compares prices on products historically, going back to when they first went on sale at Amazon.

The first product is the Anova Sous Vide Precision Cooker. If you’re unfamiliar with this gadget, it uses water and vacuum-sealed bags to cook anything to a precise temperature and is one of my favorite gadgets I’ve ever purchased.

The most popular model was about $200 last November but dropped $60 on Black Friday. It’s $139 now, but if last year’s 30% discount is any indication, the price will drop to under $100 on Black Friday weekend. Instant Pots were all the rage a few years ago.

The Instant Pot Duo Crisp that includes an Air Fryer is $149 right now. It dropped to just under $100 last Black Friday. On Prime Day this year, it dropped to $89. Look for a similar bargain this Black Friday.

The Aerogarden, a hydroponic gadget that grows vegetables, herbs, and flowers is usually around $150 depending on the model. Last Black Friday it was almost half-priced as it dropped to $80.

About that Amazon secret, prices historically hit their highs in the days leading up to Black Friday and Cyber Monday. So once the sales begin the savings are more impressive and attractive to shoppers. The Paperwhite jumped to $149 just last week.

And remember, while these price comparisons are at Amazon, other retailers will match the low price. That includes Walmart, Target, and Best Buy.