Do you have any evidence that the profit margins of Vitamin C are increasing? At least on Amazon, it looks like the price has been fairly consistent for the pas

Do you have any evidence that the profit margins of Vitamin C are increasing? At least on Amazon, it looks like the price has been fairly consistent for the past 8 years. I wouldn't be surprised if the largest cost of Vitamin C is the opportunity cost of shelf space. It can't imagine it being a common purchase. https://camelcamelcamel.com/product/B0000DJAVX https://camelcamelcamel.com/product/B0000DJAVX https://camelcamelcamel.com/product/B0019GE9HE https://camelcamelcamel.com/product/B0019GE9HE