Why the hell do I have a Costco membership?? I'm single and in my 20's. The frozen food section has nothing vegan in it. If I'm throwing a party; I can see the produce section helping me out, but otherwise it's too wasteful for me to shop for produce in bulk. And Costco doesn't take coupons.
However! Costco has some amazing finds, for ridiculous cheap. You can buy books here at cost or US prices sometimes (perfect for birthdays and Christmas), a designer cardigan for under $20, the biggest tubes of Glysomed I have ever seen (my winter skin rejoices!), and you can get things like unsweetened Coconut Milk in bulk. Perfect for my summertime homemade ice cream making! Not to mention, when my dude friends realize I have a Costco membership, they decide it's the perfect time to stock up on... er... family planning supplies. Hey, I'd rather help them buy THOSE in bulk than diapers!
So why do I renew every year? Because of all the reasons above, but mostly, because every time I see the goofy-ass picture of me on the back of my membership card (I was dragged in one morning when I was 19, grumpy and fresh out of bed!) I crack the eff up. And that's totally worth $35 a year ;).