Here in Australia, beer and liquor is very expensive (prices start at around $30 a case or $30 a bottle), but wine is cheap (can get low-end wines for $5 or less). The reason is that they're taxed differently.
I love beer, but I'll often drink wine at home (especially in winter) because of this. A six pack of craft beer is often $20 at a bottleshop, which is pushing it. I still tend to prefer to drink beer in bars/pubs though.
Fortunately I've avoided too much hedonic adaptation, so I'm content with the $10 or less wine. I find that the booze from Aldi is in general pretty good, and cheap. I quite like the 2L casks of red that they sell, $8.99!
When I'm at home, I'll buy a bottle of wine or a six pack of beer every month or so maybe, I drink a fair bit less now than I used to. If I go out to bars (which is increasingly rare nowadays), I'll spend anywhere from $30-150. A pint of decent beer at a bar might be $10 or more, and if I've had enough of them I might want to go and get a souvlaki afterwards, and get a cab home. It all adds up. I don't really do that much anymore though, I can't be bothered going out most of the time nowadays.
I don't buy many spirits, I don't drink much of them. I still have a bottle of scotch (unopened) I bought in early 2009.
I reckon I might spend $50 a month on booze overall.