The cache clearing is always a good idea.

But without inside information there is no way to know just how sophisticated companies are nowadays.

A friend and I were researching buying some flower seeds for our gardens. I don't remember the exact numbers but somewhere between $10 and $15. For the exact same item, her pricing showed $1 more when she was on her computer logged in as her, vs my computer logged in as me. We checked multiple times and always got the same variation. She is one zip code away. My neighborhood has a higher average income. I've bought more from the company in the past. Who knows just what caused that difference.

A cruise wholesaler remembers my senior age, and shows me any senior discount, vs what my son sees. I know I've never put my age into their site separately, although I've used it when making a purchase through them. So they've grabbed that fact, remembered it, and use it in my future searches.