As a single guy, I had a membership for a year, and even when I took a roommate, we ended up throwing way too much food out - and I just can't do that having grown up poor.
If I need to, I just call up the folks to go in with them
What is the best about Costco USA - self checkout lines. These are golden if you are able to stay sub-$100 (like when you just need a box of 96 granola bars and some Vitamin D pills
)