Well Katrine has given you the low down on France and I've nothing to add, except to say that I think Holland is just a smidge cheaper - for example I had a Kaufman Fusion here in France for 22 euros (31 USD) a few months ago. I have seen that same range in Holland for 16 euros (22 USD) a metre (39"). Plus in Holland there are a lot more fabric shops, here my nearest really good dedicated QS is a good hour away. My knowledge of French lady quilters (fairly limited, I used to go to a local guild) is that they buy fabric for a project - they don't stash build (hardly surprising at those prices!).
I order online, mostly from the UK like Katrine. If I'm in Holland, I treat myself to buying something I can actually stroke first! :-D
BUT on the upside, I can get a really great bottle of wine for a couple of dollars, so it's not all bad! :lol: