I used to go to Japan (and other Asian countries) very often on business. This started in the early 80's and continued thru about 1998. I NEVER found cheaper camera goods abroad than NYC mail order.
A long time friend is Japanese expat who now lives in Seattle. Since he has family in Japan still, he frequently goes back to Japan for months at a time. I recall that one trip he went in search of a camera and fast zoom lens. In the end, after much shopping and bargaining, the BEST he could do was to equal B&H prices! In order to save the most money, he should have purchased only the body in one country, and only the lens in the other country, as each country could provide the lowest price on ONE of the two.