Amazon's dirty little secret is that anything you buy from them on a regular basis, they raise the price on you, and just you. I have gone to Amazon's site from a computer that has no account, and priced something, and then went to buy it from my phone which is linked to my account, and it was $2 more on my phone, even though I was looking at the PC price which was $2 less.I bought two cans from Amazon a year ago for $.99 each. It's now $19.80 each. (!!!)
They even charge Macintosh users more than Windows users based on the browser name. If you go in using Safari, the price will likely be higher than if you used IE or Edge. I've got to start a study on this. I'm sure if I could prove with enough evidence that they overcharge some customers over others, I could bring some kind of class action suit against them.