Costco, yes and no.

Yes, Costco can be a great place to shop.
And it can be a mistake to buy things there.

One of the basic organizational shopping guidelines (so much nicer term than rules, don’t you think?) is:
How much is enough?
Another guideline is:
Where is this going to live when I bring it home?
And,
What’s the real cost of saving money?

It’s easy to get caught up in mindset of bulk buying must be a bargain, or
I’m going to need this eventually so why not buy a lot of it now, or
this might not be here next time so I should grab it while I have the chance.

However, all those bargains, multi packs and deals are going to need to be stored somewhere once you get them home.
Plus you need to remember you have them,
find them when you need them and
use them up in a timely manner.

Every square foot of your house or apartment costs you on a daily basis.
(Divide your mortgage or rent by your square footage and see what you pay for each square foot)
Is the money you ‘saved’ worth the storage cost involved?

If you end up throwing things away that have gone bad,
or never using them,
or stuffing your closets to over flowing just to store all these bargains: 
What’s the real price of all this saving?

Be mindful of what you really eat.
Pay attention to what products you really use and in what quantity.
Remember the One in One Out rule.
Be an intentional shopper.
(and not just at Costco)