i really like liquid multi-vitamins (typically they contain a lot more vitamin complexes and are supposedly better absorbed by your body).
usually they are pricey at $30 a bottle on average... but like you said, it lasts you for months and does something positive for your body, vs spending the same on a few hours of poison.
p.s. the only downside is that most liquid multi vitamins taste pretty bad, but then again vodka/whiskey/tequila/whatever doesn't taste all that great either.