How big is the cube(gallons?)? If you have a big enough pot to boil 3-4 gallons of water, you could easily do a partial boil extract and ferment it in the cube if it's big enough. In which case just get an extract kit from your local brew shop and you're good to go.
Edit: Not sure how tight of a budget you are on, but you can get a brew setup for less than $100. Midwest sells a basic kit with buckets for $59(http://www.midwestsupplies.com/brewi...pment-kit.html
), that would atleast get you going if you wanted to get into beer brewing, though that kit assumes you have a pot to do the boiling in.