Thanks to all ! Porcy, my budget is 100-200 Euros, a little more if needed.
If you are able to mount the cartdrige by yourself, and if you choose an american or japanese manufacturer, like Denon, Sumiko or Grado, have a look at on-line shops based in U.S. like Acoustic Sounds and MusicDirect. Usually better prices then E.U. distributors. At least in Italy it's cheaper to buy interconnect, cables and cartdriges overseas (all the stuff that doesn't need any assistence beyond the warranty), pay the import duty, and still save 20% of the total. Euro rules, for the good and the bad.
edit. Overall, if I were you and I could afford it I'd go for a Sumiko Blue Point, MC, high output.
Consider that with MC the stylus is fixed, so you have to change the whole cartdrige, that would be a reason to ask to french distributor/sellers if they have some discount about cartdrige replacement. On the other hand, as I said above, over here I could save 20% from overseas online sellers. It might be that buying a brand new cartdrige overseas could cost the very same of the retipping/replacement by official national distributor/seller.