Scott Jesmore had all the right answers, except clarification on alcohol. In NY Costco can't sell hard liquor or wine. The attached liquor store is a completely separate entity from Costco. The beer and malt beverages in the store still require a Costco membership.
That's something they won't do and it's disappointing.
Not to my knowledge
You can eat food without a pass
You must have a membership card to make a purchase from the Club. No day passes.
Costco does not have day passes. You need a membership for regular purchases. As long as the entrance greeter doesn't ask to see your membership cards, there are some exceptions. According to online sources, you can purchase prescriptions, eye exams (but not the glasses), food court items, and possibly alcohol without need for a membership. (If they ask for a membership card you can try telling them you're there to purchase one of the above. Additionally, you can also purchase at Costco's website without a membership but will be hit with a 5% surcharge. Beyond all that, you'd need to purchase a membership.
You can go and look around then decide to join
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