[m_mueller]

I'm not exactly sure what your argument is. Sushi is local to Japanese culture, and just as you thought, Japan has some pretty decent Sushi for ~10$ (1000 yen), that already beats 99% of Sushi in foreign countries. I wouldn't call it gourmet, but it's prepared by a chef who knows what he's doing. That it costs more in California, where you don't have Tokyo's crazy Tsukiji wholesale fish market that allows them to have the world's best and freshest fish for reasonable prices every morning for 7 days a week, and where the job market for skilled Sushi chefs is much more a seller's market, doesn't surprise me.