For some products it can be cheaper to buy retail. The retailers use their buying power to get a lower price than anyone else gets. There have been incidents wh

For some products it can be cheaper to buy retail. The retailers use their buying power to get a lower price than anyone else gets. There have been incidents where all the mechanics go buy their oil from Costco, or all the bakers go buy their butter from Walmart. The savings were enough to justify it. You can generally skip the sales tax if you have a business license, or there's some way of registering purchases as being for resale (seems to vary by state here in the US).