I go to Costco for almost everything because it is actually closer to where I live than either the grocery store OR Arco. The cash back on my Amex card is also another major influence on me going to Costco. Because I live so close to a Costco, I often get in and out for under $50. Many times I have gone just to get bagels. The time it takes to park, walk a mile into the back for the bagels, and return to my car takes a long, long time. In that respect that is the true cost. I can easily avoid the crowds.