My girl was looking for a dress for Halloween. Yesterday she found one on Amazon for € 35 and put it in the cart, but did not buy it. Today she looked it up again and it was € 50 so she asked me to look it up with my phone with my Amazon account - it turned out to be € 23 for me, less than half of what it’s for her!
There are definitely different prices when I’m logged in vs when I’m not. My wife sends me a links to products, and I usually open any link in incognito windows. Several times I was not seeing the same price as her. Opening the same link on my account would show the same price.