Costco electronics prices are competitive and have the best return policy and practice in the industry.
Non-perishable goods are canned or sealed items that can be kept for years in cool, dark, dry places.
Unopened milk does not last nearly as long. Still, it can last for ~3 weeks at home depending on how it's preserved, how old is was when you got it, and if you keep your fridge cold enough. Which again should be plenty if you actually use milk.
Really the trick to bulk buying (besides liberal use of your freezer) is only bulk-buying things you actually use a lot of. I'll buy tomatoes at Costco because I'll eat them but I don't eat nearly enough apples for buying a massive thing of apples to make sense.
Not every milk is UHT but every grocery store offers it.
But what about Costco (or other bulk-only sources), which is, really, the whole point of the thread (and original comment)?
In some cities I've lived, the expiration date of milk was often two or three weeks out. In other cities, it was 10 days maximum.
I think it's because dairies (and cows) are not equally plentiful in every part of the country.
One thing I have noticed is that in the places where regular milk expires in 10 days, the organic milk (which one family member drinks) doesn't expire for a month or more.
only limitation is: infant formula and false advertising (defined in https://www.law.cornell.edu/cfr/text/9/317.8 )
It seems the only places where it's "common" are Italy, Turkey, Switzerland, Germany, Czech Republic, Brazil, Portugal, Spain, France, and Belgium.
[0]: https://en.wikipedia.org/wiki/Ultra-high-temperature_process...
(To be fair, I think I'm the only person I know who does this)