Prices - Japan versus US
Most Americans (who have not traveled to Japan) believe that Japan is very expensive. I think this comes from the pre-bubble times in Japan (before 1990), when I think prices were very expensive. I remember hearing things like a cup of coffee for US$6.
But prices really aren't all that bad. As a matter of fact, my girlfriend commented that we spend more for meals in the States, even though we were getting better food and service in Japan.
One thing to consider is that in Japan, the listed price at restaurants is inclusive of everything. In America, we add tax (about 8%) and tip (about 15 to 20%). Our most expensive meal in Japan was a Kobe Beef dinner in Kobe. The price was JPY5500 (about US$47) per person. This is equal to paying about JPY4400 (about US$37) in the US (which after you add tax and tip, comes to about JPY5500). A steak dinner in the US with similarly high quality beef would probably cost more than this.
Of course, there are areas that are more expensive. Travel is one example. There are no freeways in Japan - all of the highways/freeways/expressways in Japan are tollways. And they charge by the distance you travel.
Trains are a convenient alternative, but they also are not cheap. Particularly if you use express trains, as they charge both for distance gone and add express train surcharges (a bullet train costs about twice as much as taking a local train to the same location, but does it in much less time). Thankfully, they have rail passes for foreigners which let you use the trains all you want which are reasonably (about US$250 for a week). They only work on JR trains (not the other lines or local subways), but that gets you most anywhere you want to go in Japan.