I think we probably save a small amount shopping at Costco (meaning our savings at least pays for our membership, plus some).
There are surprisingly a lot of bad deals at Costco, so you have to be a smart shopper and know your prices.
The items I buy regularly at Costco are:
Toilet Paper/Paper Towels
Clorox Wipes
Tide Laundry Detergent (out of convenience)
Half & Half
Organic Butter
Chicken Breasts (out of convenience)
English Muffins
Outdoor Rolls (for hot dogs & french dips)
Tortillas
Feta Cheese
Organic Spring Mix Lettuce
Organic Baby Carrots
Bananas (out of convenience, if I need a lot)
Organic Frozen Green Beans
Greek Yogurt
Craisins
Organic Tortilla Chips
Kettle Chips
Mocha Frappe Mix (OMG, Yummy!!!)
Izze soda (on coupon only)
Strawberries (only occasionally...I prefer organic)
I don't buy Milk at Costco because it doesn't list where it is from. The organic milk I buy is from locally humanely treated animals. I don't think the animals Costco sources from are humanely treated (as far as I know). Same with eggs. But, for those that don't care either way, I think the milk & eggs are a good price.
Occasionally we will see a household item we need. We always check prices before purchasing...usually Costco is a better deal. We also take into consideration their amazing return policy which is worth something to us. I hate returning items unless I have a big reason but I have returned a few things to Costco before and I get my money back with virtually no questions asked. I love Costco!