I have great vision insurance. Every state I've lived in, there's been no issue at my local Costco vision center. Until now. It was nice of them to tell you up front they don't bill insurance and that they're out of network for pretty much everyone. Oh wait, they didn't say that.
Be prepared with cash in hand for your visit.
Also there's no waiting area other than the hard metal benches in the Costco vision area outside of the "vision office".