If Amazon.Com wants to lead the online retailing world in the charge to compete with brick-and-mortar outfits, changing the prices of products at random probably isn’t going to help their cause. They’re saying it’s just a test, but really, what stops them from doing it as a regular practice. If they determine by your customer ID that you tend to pay more for stuff, how do you know they won’t make sure to mark you up more than a person profiled to be a cheapskate? Grr.