If you want foma or rollei paper you could try maco direct:

http://macodirect.de/

They have an English ordering page and take paypal as well as credit cards. Postage is calculated before you checkout so you can see what it will be.

I just ordered some papers that I could not get in the UK (2 boxes of 12x16) and postage was about 10. They were cheaper too on a lot of items than UK suppliers.