IF your production is in your city's newest, snazziest, still on page 7 of your local paper, civic owned facility and your city's mayor is still especially proud of it. In the middle of a three day Holiday weekend you can even obtain a container or two or three or four from the back door of your local Red Cross / Blood and internal organ / transfer facility. (Don't ask me how I KNOW this.)Yes, dry ice fog can be fairly expensive. Luckily, we found a local industry to donate it, and they are open on weekends. It gets really expensive if you have to try to keep enough to last all weekend. I think most Publix stores carry dry ice, and are open weekends. Publix is where we were getting our dry ice before we found the donated source.
Up here North of Little Donnie's Walls, I don't believe I've ever heard of Publix. Hardly surprising, you're likely not familiar with CTC (Canadian Tire Stores).