I've had a Costco membership for years. I am with you on how they treat their employees especially compared to Wal-Mart and even Target. But, in terms of what you'd be able to shop for there. They do have a lot of organic, but whether it would be worth it from a food perspective would be something that you just have to determine. You definitely can go in as a guest with someone who has a membership.
I always get my gas there as I have the Costco branded American Express. It's always the cheapest gas in the area and with using the AmEx card with it, I get another 3% off (gets applied to the dollar back at the end of the year). I have an executive membership, and the $ back program basically pays for my membership fee every year which is nice.
Costco insurance is good as are their vacation planning services. They have great photo store and pharmacy, and lots of household items. I've bought a lot of children's clothes there for the grands. Also, a great tire and battery department that is significantly cheaper.
I also always buy things like laundry detergent, soaps, toothpastes, TP, paper towels, dog food, etc., there in bulk. I wait until they send out a coupon on them and stock up.
Obviously, I love the place both for socio/political reasons and for what they carry.



