I do notice OP is after European brands and then it would make sense to order from EU. However, if "mainstream" brands are of interest, such as Kodak, Fuji, etc. then for economy I can recommend Hong Kong. A roll of Fuji Acros 120 costs HK$18 (US$2.31) over the counter and Kodak Tri-X about HK$27 per roll of 120. C-41 is in the same price range, from HK$20-30 a roll, depending on brand etc. Shipping costs to the US are probably very similar to EU-USA.