When I tell acquaintances that I'm going to Japan (I go every two or three years these days), the most common reaction is, "But isn't it awfully expensive?"
Over 30 years ago, the popular magazine program 60 Minutes did a feature on prices in Japan. They went to Tokyo and did everything in what was clearly the most expensive way possible: cab from NRT, meals at exclusive restaurants, expensive international hotels, including a Western-style breakfast with much more food than most people eat for breakfast, and of course, the $80 gift watermelons.
That TV program has evidently become embedded in the American mind.
Backpackers who have just come from Indonesia or Thailand also contribute to the impression that Japan is impossibly expensive. Here they have been trekking through the inexpensive countries of Southeast Asia, eating at street stands, and suddenly, they come to a First World country, and it violates their impression that Asia is supposed to be cheap.
For that reason, more information about budget travel would be a good way to entice more Western tourists to Japan. Emphasize its safety and the fact that you can drink the tap water. Feature interviews with Western tourists who have enjoyed budget trips to Japan. Show what a room in a business hotel looks like. Show examples of some of the teishoku (set meals) available in department store and other restaurants.
(By the way, tourists from other Asian countries may not know that Japanese tap water is safe to drink.)