I live alone, so buying in bulk at CostCo is tricky sometimes. If I eat it all, it’s generally a big value but what if I don’t eat it all? 
I see some people at the store saying “I won’t eat all 36 eggs before the expire” but I ask, but are you saving money even if you only eat 24 of them and throw the rest away. Personally, I hate to be wasteful but paying more for less eggs somewhere else is also wasteful.
In case you don’t know, CostCo is a bulk warehouse of food (and many other non-bulk items) similar to Sam’s Club or BJ’s warehouse.
Since you asked (you were going to ask, right?) these are my staples at CostCo.
Regular Food:
EXTRA LARGE EGGS, you have to buy 36 eggs at a time, I eat one egg a day, so sometimes the dates work out close for me, but generally I don’t get to eat them all. But even if I don’t eat all of them as long as I eat at least 24, I’m generally saving money. Since they have the date, I know how many I’ll have left near the end, so I can drop those off (in advance) at Mom’s when I visit.
WATER the 16 ounce bottles are the same price as the 8 ounce bottles (sometimes cheaper). Why would any one buy the 8 ounce bottles (water is actually good for you). Water lasts a long while and I drink a lot. The generic brand is almost always cheaper than anywhere else. To be clear: at home I drink water from the fridge, the bottled water is just to take with me on the go (I actually leave it in the garage); I know I should use reusable bottles, but that’s money and time so I think I’d end up drinking less water and more soda.
BANANAS they have a huge bag at a good price, I don’t always get through them all, but value-wise I think it works out. Regardless, I eat more of them because of that and fruit is good for me!
MICROWAVE BACON, I have two pieces a day and the date is generally months in advance. There is incredible savings in the larger packaging on this. Sometimes you can find good sales at regular grocery stores but these are really good prices (and large pieces of bacon).
LUNCH MEAT, I get the Hillshire Farms brand but I have to get 3 pounds of it! The date is usually in the future aways and the 3 different flavors are in 3 different 1 lb. bags. In the summer months I usually eat it all (I always pack a sandwich to take biking, hiking, blading or reading) and it’s a huge savings. But other times, even if I only eat about 2 pounds, I think I at least break even.
BUTTER, I put in the freezer so it lasts forever.
ORANGE JUICE I drink (at least) one big glass a day so I have no problems. I buy the Tropicana (4 ½ gallons) so it’s about the price of an average sale (but way better than non-sale prices). If they’re way on sale at a local grocery, I stock up there.
BREADS and BUNS for the above sandwiches, I buy and put in the freezer then I pull out 3 or 4 at a time and put in a zip lock bag.
MILK, I only have to buy a gallon and it’s generally a great price (or an okay price), I usually get this here.
CEREAL, I get it every so often, but I’m generally disappointed, it seems more crushed than smaller boxes, I break even I think, but I’m disappointed so I don’t often get them.
Snacks:
SUN CHIPS has 30 bags in a case and is usually good for 6-8 weeks (and will last much longer than that). Good value for me generally any time of year (but I eat more of them in the summer). It seems like they have these on sale (CostCo coupon) a few times a year.
TRAIL MIX (asst. nuts, M&Ms and raisins) has really good dates, but the price on these have really gone up. I thought they used to be in the 40-50 cent (each) range and a few months ago I noticed they were 55 cents and a few weeks ago they were 65 cents each! I passed last time, but I really miss them, I might cave on these next week. These would be a better value for me if there were 24 smaller bags in there instead of 18 larger ones…
WELCH’s CHEWY FRUIT SNACKS in the tiny bags, (I don’t know the actual name of these). These are hugely cheap and have a huge quantity and are way cheaper than at the grocery store. I like them a lot (sometimes I eat two or three), a few friends like them, but my mother thinks they’re awful!
RICE CRISPY TREATS is one I occasionally get. They last forever. A decent value. If they’re on special (CostCo coupon) it’s a great value.
Lunch:
While I’m there, I’ll get lunch. Usually a bottomless Coca-Cola and a hotdog (great value, but the hot dogs are a little boring there) or a large slice of pizza and a coke (grab some extra napkins to dab off the grease).
I get a variety of other things at CostCo, but these (and gasoline) are what pay for my membership.
This post started as a really long (slightly off topic) comment over at The Simple Dollar so I turned it into a longer post and posted it here instead.
