I have yet to visit a co-op that had cheaper than grocery store prices. Every single one focused on quality over cost savings.

This was not always the case. 30 years ago the customer base for bulk co-op places were lower-middle class/poor folks who had a decent amount of financial acumen. You'd go there with your own containers and buy staples by the pound. Or special order that 50lb bag of oats or flour for 1/4th the per-lb price of the local grocery store.

They slowly morphed into bougie health nut/conspiracy hippie stores during my lifetime. Closest thing I've found to what I remember them being are food service stores which tend to require a business tax ID to buy from.