Well if I remember right to make about a gallon of "ethanol" is a couple packs of yeast, 10 pounds of sugar, and some sort of mash, wheat, corn, fruits, taters, just most any fruit, vegetable or grain, fill up the 10 gallon metal pot with water/mash/sugar/yeast, let it do it's thing for a few days until it quits bubbling, then run it off (applying the all important taste test every so often to be sure it's running "pure" enough). So unless sugar has gotten a lot more expensive you should be able to make it yourself for well less than $20 per gallon.
I'm just wondering is there any reason you shouldn't use it? Will it foul plugs or whatever. I've read people using just plain water injection and just plain methanol, or some sorta mixture in between so what about ethanol, if there's no compelling reason not to use it it seems like a perfect solution. Pablo seems to not have any warnings against it so I figure it's the ultimate DIY project, and unless some reason against it comes out, I plan to give it a go when I finally get around to putting alcohol injection in.