- large sizes, low prices
- don't carry all brands of their items but do carry very good brands (often the best) for each
- the best darn hot dog deal on the planet (which is outside and requires no membership): a quarter pound Hebrew National Kosher Hot Dog and a bottomless soft drink for $1.50
- best darn rotisserie chicken deal on the planet (don't know WHERE they find chickens that big to roast..$5 each)
- a pretty darn good pizza deal (also outside). 2 big pieces for $2.
Everything is bigger, and you will become bigger also because after you buy that 3 lb jar of beautiful cashews for $9 or whatever, you will then eat them faster because they're there and you don't want to let them go stale or anything...
You can good value from them if you buy large amounts of stuff.
Go browse their website www.costco.com for some idea. Not everything in store is on the website and not everything on web is found in stores.
In addition to the other comments you will also (hopefully) find extremely high quality high value food products as well as wines of that's allowed in your area. You'll also see unique items not easily found anywhere else. The inventory is very seasonal. If there is something you want don't hesitate or it might be gone.
I also have to chime in that their pizza absolutely rocks for the price and quality. I hardly ever leave the store without a piece of combo and a soda. Not a bad deal for like $2.50 or so.
Great prices for household cleaning items, seasonal items, and food. Be careful with food items. It is easy to buy the large quantity of certain items only to have them go bad or get stale. Things that can be frozen are fine. I find it very easy to buy more than I intended to. Some items are a better deal in the regular supermarkets when that item is on sale.
Some items only show up once, if you want it - buy it - it might not be there the next time you go.
All in all - it is worth while to be a member - you can save some money.
And your major seasonal holidays will be about 3 months earlier ("Christmas started a month ago here, and trees/lights/gifts/etc. will be gone by early/mid-December).
Costco generally avoids sales on end of season items by watching stock flow--once the sales have peaked/flattened (not peaked and declined), they cut off further orders/stocking. Hence specials/seasonal things tend to disappear quickly.
Fun thing too is that the Costco card works world wide--so it is fun to go to a Costco in a different country (went to the Costco in Taipei, Taiwan earlier this year--some things were the same, but lots of localized food too--wife and in-laws love it).