Depends the day and the product.
One day Amazon is better than NewEgg, the next day Best Buy is better than them.
Weeks before Amazon days my friend saw a 800W Power Supply go up for sale on Best Buy. A brand he loves. So I look it up on Best Buy & Amazon. It's Amazon's every day price. So I picked it up.
Then I saw waiting for a 3080 TI OC, went great price on NewEgg, next day Amazon beat it, the next day Amazon beat itself. Sadly I used points, credits, etc to get it on Amazon with the first sale so I lost out on another $50+ discount... but in the end well worth waiting and shopping.
So for me, time and patience and LOTS of shopping different stores till you find exactly what you want at the price you want