Don't they do music shops in France, then?! Though I remember from my days working in a music shop that French music was a truly dreadful price, and I don't suppose the Euro has made that any better! If you're going to get it posted from abroad (ie, not France, seeing as you're in foreign parts already...) then if you have access to a British bank account/credit card, American music is cheap, even counting postage, because of the strong pound/weak dollar business. I've had several books from the USA which, including postage, cost me less than buying them here.
Does France do second-hand music shops/bookshops? That's another possible source.
I've heard that sheet music downloaded from the internet is difficult to read and sometimes badly edited, but that might just be some bad sites.