It took us awhile to adjust from weekly shopping to buying a month or two of something at a time. And at first I wasn't so sure if I was going to like it. Seven years later, I love it. I love Costco. Also an executive member and like someone else said, it's a great deal. You will get your money back if you do not make back enough to cover your membership upgrade
My favorite things to buy:
Meats (organic are so much cheaper!!!)
Fruits & veggies (same as above, organic for less!)
Dairy free chocolate chips
Nutiva Coconut oil
Jalapenos
Organic Ketchup, jelly, peanut butter
Spices (Large container for same price as small one at regular grocery)
Eggs
Power bars, protein powder
Orange juice concentrate
Chicken broth (Kirkland organic is a good deal)
canned Tomato sauce & diced tomatoes (both are organic and very good)
Frozen veggies (love their stir-fry mix)
Frozen fruit for smoothies
Greek Yogurt
I could go on and on. We buy a lot from them. My favorite time to shop is on Sunday evenings an hour before they close. The store is practically deserted.
Return policy is one of the best out there. Period.
Their cafe is a great deal. Super cheap way to grab a quick meal.