I think the Costco package also included two holsters. I hate to carry extra weight but it would be tempting to carry two cannisters in two holsters and hike with the trail name of Hopalong Cassidy.
Doug,
The Marysville Costo felt totally different from the two in Seattle. Uncrowded, very smooth slide-my-shoes- along floor, no traffic (7PM weekday), small lines, no traffic on freeway back to Seattle, easy to find and get to stuff, simpler check out, plenty of parking near store, etc.  We even got our tires inflated simply by pulling up to the tire store and having the guy come out with the hose.