Just some comments for those mixing your own from flake, something I think I am going to do.
I don't know the cost, been twenty years since I needed a gallon but your friendly neighborhood pharmacy can get the purest alcohol you are likely to lay hands on without cooking your own. They call it 99% or 100% grain alcohol. Not denatured. I think you are supposed to have a script but when you are friends with a pharmacist they don't require prescriptions for things like this. Used to mix my own liniment, mostly for the horses, sometimes for me or the wife! Denatured alcohol was a nonstarter for it as was the usual lower percentages.
The pharmacist can also get 99% isopropal alcohol but I think that other one percent is likely to be oil of some kind so I don't know about using it in a finish. Excellent for cleaning electronics and should have worked in my liniment but I was following a recipe that called for the pure grain alcohol. I might look into this. If I could get fairly large bottles it would be cheaper than the grain alcohol if it is just a little water impurity in it.
Hu