For me it wasn't the amount I spent on alcohol but the other frivolous **** that went with it. I'd splurge on other things but still seek out the cheapest alcohol possible. In a way, I think part of the reason I drank was because I enjoyed myself in other ways too by spending more on restaurant meals/takeaways/gambling/travelling/sporting events (whereas when sober I limit myself in regards all other enjoyment - something I'm trying to change).
So I'd go from spending £4 ($6) a day on food, and that'd be it when sober which was two-thirds of the time; to spending £20 on crappier food, £20 on booze, £40 on gambling, and then other stuff if there was sport going on or I fancied a "treat".