So just how much gas do you buy at a time? 500 gallons or more? I can't understand why anyone would want to store gas for up to three years. If you mix up 2 or 3 gallons at a time how long will it be before you need to tank up again? Most gas will easily last 3-6 months if maintained in a sealed container and out of direct sunlight. Just about all the newer gas cans are air tight and don't vent vapors to the atmosphere anymore.

The stabilizer isn't needed unless you plan on storing a lot of gas for very long periods of time. As for the avgas, ever wonder why your plugs foul so often or why they have all that silver-grey stuff on them? I presume you're using the avgas as a model fuel and not in your car. The oil used for the mix is a stabilizer all by itself to a limited extent.