Welcome to the forum. You'll learn a lot here. Join in on meet-ups on the strip and downtown to encourage others to practice self-defense, and socialize with like-minded folks.
I think Costco will never give up their stand of being against public safety. One more example of shallow thinkers who can't understand that having a few armed law-abiding shoppers in their store can only improve everyone's odds of survival if SHTF. Sad.
In case you haven't already noticed, Sam's Club is OC-friendly. I've shopped both Costco and Sam's a lot over the years, and find Sam's has as good as or better prices on many items, especially the big ticket products like TV's; I bought a 47-inch model there a few months ago that Costco carried at $50 more (finally have a monitor that's easy on my tired old eyes!). What needs can't be satisfied at Sam's, you'll find at WalMart (also OC friendly) for good prices. On prices alone, no need to bother with Costco.