In my case, I use about 150-200€ for midday lunches in a normal month (eating out, I'm in a client's office, and eating at my desk would means eating alone, and I forbid myself to do this anymore). So that's 200*12 every year.

If it's free food, it's money I don't get, so I don't have to pay taxes on this money. I'm in the 30% range, so free food = about 3k€/year salary.