I've been shopping at Costco for few years now. Kinda like it as they carry many items that cannot be found at other local supermarkets. Price aren't necessarily cheaper unfortunately and you have to buy items in bulk. Lately there are no more stands to taste/sample food (which was quite fun and great to try items before buying in bulk).
Arrive early to to get a car spot and avoid the massive checkout queues that can build up quite quickly, even during the week. Mostly, you can get the same or better prices at the supermarket when things go on sale, but I come here to stock up on products like coconut oil, Kurrajong Valley crackers and cheese.
So many amazing deals but SO MANY PEOPLE with huge trollies. You can honestly buy anything in bulk here. Prices are definitely cheaper and everything from lollies to a TV unit. Love their bakery section too. And it's always the best when they have free samples all around! Just bring patience with you because some people will definitely test it.
I love shopping at Costco especially during its non peak hour. They range good quality product at reasonable price. If I want to buy something I am not familiar with I would go to Costco first, in most cases I ended up buying one of them even after researching elsewhere. Products I love to buy are Frozen Pizza, Free Range Eggs, Black Forrest Cake, Choc Croissant, Kirkland's Unsalted Mixed Nuts.
I love grocery shopping and this place is like heaven. They have so much in bulk and American brands that other retailers in Australia don't sell and once you have done all your shopping you can enjoy a nice slice of pizza the size of 4 normal size pizzas right outside the door!