Unlike Canada, megabrew beer is so cheap in the US, I'm surprised you don't use Coors light or miller light for brewing water.
I remember stopping at a grocery store in Oroville WA and seeing a 16oz bottle of Miller high life for cheaper than a 12oz bottle of water.
The first part is funny, I may just try that sometime.
The second part is way funny, cause it happened to me, too. After a tough day in the sun boating, on the way home as I was getting gas, the kid said he was thirsty and there were no beverages in the vehicle, they were still in the boat, and it was all covered up. I decided to go into the store part of the gas station, to get something for him to drink.
I came back out with a water for him, and a 22 for me. The beer was cheaper than the water and almost double the volume. I told him that I couldn't pass up the deal.