Your question is not really answerable. Lunch habits in major cities in Germany are really no different from those in New York, Paris, or Sydney. Some people will have three courses with wine, others will have a sausage/kebab at a stand (ie NY hot dog cart), some will eat in their company canteen, some will bring their own lunch. I personally can't stand Vapiano (restaurant prices for self-serve fast food) but I accept that others have a different view. If you are asking about specific restaurants of a certain cuisine in specific cities, I'd be glad to help (albeit my recommendations will not be the cheapest!)