It's 92 octane ethanol-free gasoline with synthetic 2-stroke oil and fuel stabilizer. The big appeal is that it's the only convenient/local way to get ethanol-free gas here. Today I cleaned off the clearance shelf at Wally-World. Payed $2.50/can for 15 cans...
Buying 100LL avgas is getting to be more dificult, at least in my area. They've moved the 'perimeter' outside the station that sells avgas at the airport. Gotta get 'on the grounds' before getting to the station now. Homeland Security stuff...
I think your best bet would be to buy avgas (if available for you) or race gas (
make sure it's
not oxygenated street-legal fuel, or you're just buying expensive ethanol-gas), and then bring the ocane level
down with camp fuel. Since camp fuel is already around $10/gallon, you'd most likely be out more money if you octane-boosted camp fuel instead of 'octane-lowering' avgas or race gas.
You'd have to look at the specs/cost of your localy available octane booster products (to figure how much it'd cost to raise a gallon of 55 octane fuel to your target level) to see for certain how much it'd cost to go
that route. Plus there's the undersireable aspect of adding alcohol (contained in the octane-booster) to fuel that you're trying to keep alcohol-free (as stated above).
If you find out what octane level you'll be starting with (such as 100 for avgas, or 105, 112, etc for race gas) then we can figure out how much camp fuel you'll need.
With 100LL avgas you only need 16oz of camp fuel per gallon of gas to end up with 144oz of 94 octane fuel. Divide 144 by the ratio of premix you want to come up with the needed 2-stroke oil. For 50/1 you'd need 2.9oz of oil. Double the numbers to end up with a bit over 2-1/4 gallons of total mix.
With 112 octane race gas you'd need to add approximately 1/3 gallon (43oz) of camp fuel to one gallon of race gas to get 171oz of 93 octane fuel. You'd then need to mix in 3.4oz of oil for 50/1 mix. Double the numbers for almost 2-3/4 gallons of total mix.
Find out what's the cheapest, lowest-octane
non-oxygenated (no ethanol) gas you can get in your area (probably avgas, but you might be forced to run race gas). Let me know what you find, and I can figure out how much camp fuel you'll need to mix in to hit a target octane level. If you can get non-oxygenated "ag gas" then you're a lucky soul, and you need not buy
any camp fuel...