[raisedbyninjas]

When Costco sells Kirkland brand vodka and Grey Goose, all bottles of Grey Goose are sold the same way. Costco purchases directly or from a distributor. Grey Goose may or may not pay for shelf space, IDK. Purchasing premium shelf space is a common practice for other retailers and grocers. When Grey Goose is sold on Amazon, either Amazon buys it and re-sells it or Grey Goose sells it through a marketplace account incurring Amazon's marketplace fees. So Amazon can always have two listings for one product, a marketplace listing and an Amazon listing. Their Amazon listing can always be cheaper.

[mattmcknight]

They don't have two listings though. They list the prices of all sellers in one item, with the lowest price as the default.