Where I usually find the best deals. If you have time to spare, you can also setup custom alerts or your own profile to get notifications. Also in iOS and Android.

Amazon price checking and tracking tool. Copy the product page link from Amazon and paste it into the search bar in Keepa. It will show you data for highest, lowest, average price, and can also show potential past Black Friday/Holiday Deals.

Amazon price history tool. Copy the product page link from Amazon and paste it into the search bar in Camel. It will show you data for highest, lowest, average price.