I suppose you can check with other importers in Europe and have them post the fins. When the Quads were first released importers were specifically told that it might be a good idea to stock up on fins, but maybe all didn't take notice. The 13cm fins was also released later.
I can check if the Swedish importer have the fins in stock and what the price is. I'll get back monday or tuesday with more info. (I have a few spares myself so in an emergency I could maybe help out. I already sent some to southeast Europe.)