That's a big peeve of mine...stores that require you to have one of their loyalty cards in order to get
advertised sale prices. A lot of stores do that...Rite Aid as well as a lot of supermarkets.
Years ago I had a Sam's club membership back when it was $25/yr or so (mine was thru my employer). I liked their Members Mark jeans, and there were good deals on other stuff I used, though I'm not sure I actually saved enough to justify the membership. Now the nearest Sam's is close to 2 hours away and it's not worth it...there is a BJ's a little closer, but they don't have the selection Sam's does (or did...it's been probably 15 years). No Cosco's around here as far as I know.