What I save on Beano alone is worth the annual membership fee.
I buy lots of other non-perishable stuff there too, mostly for stuff I eat on a daily basis, or camping (which would make it good for a crisis too): nuts, beef jerkey, all that canned food. And then there is the non-perishable stuff I eat nearly daily, such as bread & bagels, and chicken.
The deals they have on protein powder are amazing. I searched high and low on the net, including buying in a bulk 50 pound box which was the cheapest I could find.. I made a spreadsheet for how much protein I got per dollar, and the stuff they sold at Costco, in a 5 pound bag or something, was still cheaper than that.