For experienced engineers it would be around 40-70k Euro. Depending how experienced you really are, how the demand for the language is (e.g. higher for iOS), on the stage of the company and how much equity you get.
You need to factor in the cost of living when comparing this to US or UK salaries. For 600 Euro/month you will get a nice multi-room apartment in a central area without sharing it with anybody else. Lunch in a restaurant is about 5 Euro and food in supermarkets probably the highest quality for the cheapest price anywhere.
If you do it for the money, ignore German startups. The chance for an exit is 1% and usually employees don't get equity. The pay is low and you're forced to burn out. You will not work for the next Facebook, Twitter etc.
Instead join Siemens, Allianz or other blue chip companies to easily earn 60-90k with all benefits you can imagine.
Berlin is even more desperate as most of the German "tech" scene is. No money, no users, bad execution except the successful copycat-business of the Samwer brothers.
Maybe someone with enough karma could create a poll...