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!
Camelcamelcamel is also good for seeing pricing shenanigans like this too. A box set a relative asked for was marked as $100 but on sale for $30 and checking camelcamelcamel I could see it’s rarely listed at its list price and basically always marked down to $25-35 with spurts of time at $40-50