As I stated in my previous post about GFS, I rarely buy normal groceries at any warehouse. However, there are great deals to be had in other sections. At Costco I particularly LOVE their bakery. It's not always the cheapest, but the quality is outstanding. I really like their half sheet cakes that are $16. You get to pick a design, the cake type, frosting type and a filling. And they are so yummy! Much cheaper than having a cake made somewhere else. Everything that I've ever tried from their bakery is absolutely delicious. Not always necessarily a frugal price, but for the quality, the price is fair.
Another thing that I love about Costco is their ready to bake pizzas. Good price, excellent quality. Just be prepared to bake it the same day you buy it because it probably won't fit in your fridge. Their fresh produce is priced well too. They also carry turkey burgers in their freezer section and tortilla encrusted tilapia. Both very yummy.
Lastly, the main reason I like to go to Costco is because of everything else in the store. All of their kitchen items, clothing, gifts, electronics, etc have great prices. Toys are a great buy at Christmas time.
So generally, if you stay away from traditional groceries and continue to use coupons at regular grocery stores, then Costco is an excellent deal. If you buy the cakes, you've pretty much already recouped your member fee just by getting two cakes there instead of somewhere else.