As I have noticed that article from bbc.com on fake Black Friday sale, the questions comes down to how the user would know if the prices have really dropped or it is just a price manipulation game by the platforms like Amazon.On searching around a bit, I stumbled upon  which has a kind of price audit of products on different Indian platforms which is kind of cool and I will try this out. But are there other such platforms which solve this problem? Does someone here use some useful tips/tricks to buy a product at optimal price?