It's scary how much money I spend between gas station and fast food in a month. I've cut back a lot this year and got down to around $500/month. Last year was horrible though, spending around $1,000/month with 7 day work weeks. I've been trying to make time to get lunch meat and canned food to bring costs down more, but usually I just don't have the time.
Edit: I guess not smoking would take about $100 of that too. I plan on fixing that this winter