25 pounds of sugar will run you around $25. Yeast and yeast accessories are also fairly cheap. Water is cheap. Storage can get a bit pricey depending on what you go for, but a 5 gallon water jug only costs around $10, and has the added bonus of already including the water.
Champagne yeast has the highest alcohol percentage but doesn't taste fantastic at 20%. Thus, 25 pounds of sugar will yield what, 5 pounds of ethanol? That is about 0.759 gallons of pure ethanol for an input cost of about $30 per batch plus around $20 in a single supply cost.
And of course, this isn't factoring in distillation which I don't think is entirely necessary as long as you can boil it on a stove top to get rid of the methanol. In reality I don't think you need that as long as you add some sugar or flavoring after, and that way you end up with some nice 15-20% beer or wine flavored however you want for pretty cheap. Somewhere under 5 gallons of it.
The only problem is the time investment. You'd have to have 2 containers, one to drink from and store your shit and one to ferment the next batch, but overall it is cheaper just to make.