I ahve been shopping at Costco since the 90's so I have seen Costco go through a number of changes. Some of those are good and some not so good. Lately, I have noticed that at my regular store in Wilmington, NC, they seem to be intent on constantly moving things around. I am not sure why they have done this but it is annoying and frustrating to go look for things that have been in a particular location forever, now suddenly you have to walk all over the store. It's not easy finding store employees unless you walk to the front by the registers. The other thing I noticed about Costco is in the area of clothing. I remember back 15 years ago you could buy a Cutter and Buck shirt and it would be of the same quality as you would find in a Belk or Macy's. Now the name brands use thinner materials and they just look like the same quality you might find at a Walmart. Basically I have quit buying cloths there for this reason. It is also aggravating to have to show a card to get in but you can't make a purchase without one. The in bound control is useless and dumb. I understand why they have a outbound control but if I wanted to steal from them, I would not have too much problem doing it. I won't say how because it may give some people the idea and then suddenly people are walking out with goods. So enough of the negatives.
There are many places you can save money at Costco but you need to shop them like any other store. Some of the best deals are milk, the hot dog special in the food court, cereal, breads, organic Blue Agave sweetener, butter, the $5 broasted chicken is a nice quick pick up if you forgot to defrost something for dinner, and Kirkland batteries are just a few. Another nice perk is being able to buy prime cuts of beef. That is not available in most grocery stores. Gas is always the cheapest around at Costco. It is also very nice to get a check back from Costco once a year if you have an Executive membership. My last check was $187 and change.
Costco obviously has a winning business model and it is wildly popular for that reason.