Where is everyone grocery shopping?

I know this is a pretty broken record by now, but groceries are getting out of hand and my fam has limited income. Where is everyone shopping? We shop with coupons and shop deals at Freddies and Safeway religiously, but there's only so much you can save that way. An 18 count carton of eggs just went from $8.99 to $10.39 at Freddies (yes, bird flu, i know)

Do you really save enough at Costco to justify a membership? They don't post their prices online, is Winco a better deal?