Around here we can only buy dry ice in chunks of 25 pounds or bigger...
I wish we had vending machines like yours, wet ice is a mess on a race
weekend. I usually go through 6-10 bags on a typical weekend, two days
out in a campground and travel time on each end of the trip.

Scotty

You need one of these:

http://www.bigfrogmountain.com/Engel%2040.html

It will pay for itself quickly if you're buying a lot of ice.

They run on either 12 volts or 110, freezes or refrigerates.