Not to mention I am retired, on the east side of Toronto. It's a 40 mile round trip in my truck to pick up A, and I probably have to make trips for the oxy also, depending on the rate of use, I'm not going to stockpile gas in my suburban home. Gasoline is 6 bucks a gallon at the moment. Plus up here industrial gas, like A, is about twice the cost it is in the US, with the enviro taxes. If I was working I don't think I could get gas at all outside of bank hours. In BC some retail super stores sell it, but not around here. Plus the bottles are expensive to buy, they are not accepted at different sellers, and two local places have closed down in the last 5 years, so you can end up either traveling even further, or buying new 160 dollar containers.

I can get propane about 300 yards from my home. If I really wanted to get tricky I could run my system on LNG from taping a pipe, and I could use a concentrator for the O2.