I was there in August and heard is was 30-40% less than the Bay Area/NYC salaries. The few web developers I talked to about salaries shared they were making 30-50k euros a year. That seemed pretty good.
It might not seem like a lot, but cost of living is also a lot less than NYC/SV.
I live in Berlin ( working as a front-end developer ) and that is correct. My rent is 700 Euro for a small flat in Mitte ( city center ) and yes, Berlin is a cheap city in terms of food, party, rent, etc. Anyway most of the people are not here to make money as far as I can see. Lots of hipsters and other people just join the city for it's special "culture / party / art" kind of spirit.
It might not seem like a lot, but cost of living is also a lot less than NYC/SV.