In college we did something similar, at our local grocery / liquor stores we found that bottom of the barrel 5L boxed wine (Franzia, Vella etc) was cheaper per alcohol serving than even the cheapest 1.75L of plastic bottle vodka or similar. (Although it was close).
Many games of 'Slap the Bag' ensued, many hangovers were had.
Ahhh college, makes me wonder how I ended up with a 3.5+ GPA in Engineering.
Now I just ... drink less. I enjoy scotch and you don't need to spend big money to get excellent scotches.
Also *puts beer snob hat on* most people slamming back beers from a can obviously don't care about the taste, but if you actually pour a beer into a glass you can enjoy the flavor a lot more even if it's not a high end craft.