It's becoming a well known fact that animators in Japan do not earn much money. Most of the names in Japan making money are the one's most of us American fans are already familiar with.
From how it seems, at least in terms of salaries, original American animation doesn't always pay a ton (especially for the unglamorous positions) but it DOES pay better for westerners than working in Japanese animation.
I don't know the actual figures, but after reading a fair amount of articles on animation in Japan and the U.S., and interviews with voice actors, there does seem to be a partial consensus. Japanese anime doesn't pay all that well, and the amount of passion being put into anime is not proportionate to how much money the industry makes as a whole.