I originally started shopping at Stater Bros becuase they do not have the club card - you know, that stupid silly card you have to carry around in your wallet to get a discount. Stater Bros does not have that.
As for union store, non-union store, I don't pay attention to that in where I shop. If I thought about it on those terms, I would shop at Stater Bros because it is an independent. There are far too few grocery companies here.
Kind of interesting to think about what has happened to the grocery industry in the Western U.S...Three companies buy up a bunch of independents. Eventually prices rise, overhead creeps up. Whamo, you have a situation ripe for someone like Walmart to come in.
I buy many of my packages type things at Super Walmart. It is considerably cheaper. I can think of two products off the top of my head for example. I buy six packs of Yoplait yogurt. $2.19 at Super Walmart, $2.79 at Fry's or Safeway. A box of Nutri Grain cereal bars, $2.50 at Super Walmart -up to $3.79 at other supermarkets.
I generally buy two of each a week total at WalMart 9.38 vs 13.16 at other grocery store. Or in percentages about a 40 percent savings.
Ofcourse, the pain of actually being there has to count for something.