I think it's the lack of price vetting on Amazon's part that makes me hesitant to buy certain things there, e.g., groceries. That wariness happened after buying several packages of dried beans that were also available at Walmart (a retailer in the US), and then realizing I had paid literally three times the Walmart price.

Now I buy directly from Walmart if something's available there, because I have more confidence that their usual price controls are at work.