With a 6 year experience I'm earning 36k. For me it looks like it's a little below average for front end dev (around Marseille. Paris is different, salaries look much higher there).

A friend of mine with a 3 years experience just got a 45k salary in Aix en Provence for C++ qt gig. I reckon it's above avetage but not that much above. But he is very good at negotiating his salary.