Bupie, let's get serious again (now that PH is out of the game, youth!): It would actually interest me to hear your impression of which prog groups and albums one listens to in France, and if there are any regional differences within France.
Frankly, this is too much to ask
I am pretty sure that Dream Theater has a lot of fans and sells a good amount of copies. Some prog metal bands like symphony X or Opeth certainly find an audience among the metal fans but, for instance, a band like Evergrey fails to gather more than 200 people at their gigs, even in Paris, so ...
Apart from that exception, I think that there is a tiny but faithful fanbase for "classic" neo-prog bands like Marillion, IQ, Pendragon or Arena but it doesn't mean a lot of sales IMHO.
Concerning regional differences, I have not a single idea. I would say that, from what I have noticed, metal (and so, supposedly, prog metal) is more popular in rural areas and small towns whereas symphonic or neo prog is more praised in big cities. But this is a remark based on personal experience, not on scientific statistics ...
By the way, Nicky, no offense but you should integrate the quote factor to your posts : it helps to the readibility of discussions, sometimes