check out the post I made about this the other day. I personally think costco is not making THAT much profit with their gold sales when you factor in the fast secure shipping, fees, storage and handling etc etc. If anything they break even on the sales and bring in the real money by getting new members.
They are always looking for ways to add value for their members and selling gold with the opportunity to get 4% cash back with their black card + credit card
RE: Costco Now Selling Gold Bars