These co-ops may even be able to connect you with others. It has been a blessing for our family of 7. Another Co-Op Advocate I buy almost nothing at our local grocery. Instead I purchase most of our food from a whole foods coop. Our coop group consists of 8 families.
Many items are available only in cases, but members of the group can arrange to split a case.
Once a month I sit down with the extensive catalog and my shopping list and create my order. I have created forms on my computer that make this simpler for me. I then e-mail the list to the person in our group who collects the individual lists and places the group order. The unloading and distribution takes about an hour. Though this might sound like a lot of work, for me it takes less time than running to the store more frequently.