If you are looking for something cheap and don't care much for taste then you could always get Red Dog beer.
It's $6 for a 30-pack and according to a friend the taste is basically "straight yeast."
As for cheap liquor, here's what I've have had, and don't plan on having again:

Rum - Port Royal
Vodka -Bartons, Zelko, Popov
Whiskey - Early Times