the best way to buy j-pop cd's

[Lumix]

I live in Europe and here is very expensive to buy any j-pop cd, cause almost no one (in czech republic) know what "j-pop" means. "Ayumi Hamasaki." "Kawasaki? You mean that motorcycle?" And Gackt? No more words. In my place paypal isn't allowed. I really want to buy some Gackt CDs! Is here anyone who knows good page with j-pop stuff? I mean cheapest. But with some "quarantee" of original stuff. (i know yesasia.com but it seems to be very expensive) I've heard that in Germany is possible to buy some j-pop! Is here any German who knows something about this?

Thank you all for your help! I will really appreciate any info!