ORIGINAL: Fuel Dinosaur
http://www.geistware.com/rcmodeling/mixing_fuel.htm
It makes sense to mix your own fuel if you use about 15-20 gallons a year, or if you just like to mix up your own fuel. It is getting very difficult to obtain nitromethane, but there are sources in the U.S.
I think it makes sense to mix your own even if you use 1-5 gallons a season. For me, its down to the cost per gallon. I have cars and airboats. 20% Car fuel is $32-$35 a gallon, and 5% Aero fuel is $28-$34 a gallon. I can make 20$ car fuel for less than $20 per gallon, and aero fuel for about $12 a gallon. The up-front costs of buying the chemicals may seem counterintuitive, but when you figure you can make 7-8 gallons or more for $120. 2 gallons of car fuel and 2 gallons of aero fuel would cost me $120 plus tax at a LHS.
I honestly had a harder time tracking down methanol locally than nitromethane. I had to order the nitro from out-state.